redbird_400

I currently have a TBI. Later mods for now are going to include a cam and a pair of heads. For now my question is " Is there any performance gain from swapping From TBI to TPI" Is it worth the trouble? For looks I know it is but is it worth it for the money?

88TPI406GTA

Yes, ditch the TBI...or go carb if your 400 is going to be over 500 HP. The TBI guys can't make the same HP levels as TPI-based systems...well, theoretically, they can up to 360 HP. Anything over that requires forced induction and a lot of tuning headaches...

I have picked this up from observing the woes of people tuning on DIY-PROM and a bit from the TBI board...

Good luck with your decision.

nsimmons

be aware a stock tpi cant make more than about 325hp, either go with a carb or a superram/miniram setup

Your tbi in stock form is good to a little over 300hp.

Jza

Yes.

tpi_roc

Carb is "worth it" But tpi's "Worth" is in the eye of the beholder

Stricktly on a hp per dollar basis TPI is NOT "worth it" (over carb) but anything is "worth it" just to get rid of tbi

88 WS6 TransAm GTA

iTrader: (1)

Not bashin, but where did you come up with either of these statments? Because neither is true. TPI can support more than 325, it just wont be up high, and will have a **** load of torque to back it up. And I have yet to see a N/A TBI car break 13's.

nsimmons

from the hundreds of owners on tpi cars on corvetteforum. A stock tpi cant make much more than 325hp, it just cant flow, thats why people swap in a super ram or miniram. Remember im taking the stock 1.9" runner setup. You can also do the math and find out the same thing. Sure you could squeeze more with some creativity, a larger engine, etc, but most built up corvettes with stock tpi dyno just around that mark, then after they swap to an aftermarket tpi setup they gain another 75-100hp

As for tbi, the stock bore size gives anough airflow to support approx a 300hp engine, you can do the math

Ive seen plenty of n/a tbi 350 cars run 13's, mines almost there, my buddies is.

Your correct in that a tpi car will have a crap load of torque, but it cant flow to make serious hp

If you could show me a 400hp stock tpi car car, i'd like to see it, but in the 4 years ive been on vette forum, i've never heard of such a thing, and with 35000+ members im sure someone would have.

As for the original question. If you can afford it I would go with a stealth ram or miniram on your engine, a 400's going to have alot of torque, so i'd pass on the super ram.

Or you can go with a monster carb, if emissions arent a problem for you, but a real injection system like the miniram, will be much more versitile, much more effieicent, and make more power than a carb, as it will outflow one. With that said a carb will be 1/3 the cost. So go with whats best for you budget/situation.

RCR

Sure. Makes switching to the LT1 intake a lot easier

ir0cz

Wrong....a STOCK TPI unit can flow over 325 HP. Besides, even if that were the case, that's why they make aftermarket manifolds, runners, and plenum.

300HP? I dont think so...not a stock TBI. That's why TBIers switch to an aftermarket TBI after they get up to 220HP or so.

Yea, maybe (i doubt it), but we've seen plenty of TWELVE second 350 TPI cars....some faster.

Once again...that is why there are aftermarket manifolds, runners and plenum. I've seen 400HP 350TPIs w/ modded TPIs. I haven't seen a single 300HP tbi guy...that's a big HP difference.

No, fuel injection will not make more HP than carb. It maybe pretty close, within 10 HP, but it will not make more.

ir0cz

Now back on the topic. I swapped from TBI to TPI on my 350 a few months ago, and so far it isn't worth it...let me explain. My engine has stock heads and cam....so swapping from TBI to TPI didn't get me much HP (maybe 20) and i picked up some good TQ...but I have stock heads and cam, so it's not like my engine was being held back. Once I swap on my heads and cam I'll be glad I did it (this is why I did it). the gain of HP from a straight up swap from TBI to TPI shows how much better TPI is. But now if you are building a serious motor, then TPI is deffinately the way to go if you want fuel injection. The reason people swap from TBI to TPI isn't for the little HP gain, but more cause they know that when they get up into serious HP numbers, the TBI wont be able to handle it...it would become the bottle neck.

To answer your direct question....swapping from TBI to TPI will pick you up some HP and lots of TQ.

If you plan on swapping on heads and cam, then it is deffinately worth the money, because the TBI just wont be able to keep up w/ the engine.

nsimmons

The only reason you gained that 20hp was because in stock form the tpi outflows the tbi by about 110cfm. That numbers straight from a flow bench, its legit. Any wadda you know, by modifying my intake to match a the tpis flow i gained the same 20hp.

Swapping over to a stock tpi, then attempting a buildup is extremley foolish, when you hit the 300+hp wall you'll be pulling it all out again and going to an aftermarket setup.

Either swap to a aftermarket tpi, or leave your tbi on there. Otherwise you'll be swapping twice.

As for irocs comments.
Im talking from experience and personal observation, you dont seem to have anything to backup your claims.

show me one 400hp NA tpi car running 12's with a completley stock tpi, no porting, no siamesing..stock, you cant.

My argument is 325hp for a stock tpi, not modded in anyway, shape or form. You mention 400hp tpis running 12's, they sure as hell didnt do that N/A with a stock setup. I believe traxion is one member who runs 12's, but he has a miniram, far from a stock tpi.

My friends car has a zz4 and dynoed 255rwhp, with the stock tbi's
Now it is a crossfire car, but the throttle bores are the same size as the 305, and the manifold is just a different configuration.

Thats 306 flywheel hp, the throttle bodies are strangling the engine, thus stock tbi has about a 300hp limit. If he was to change to 2.13" tbi's with larger injectors, and give the zz4 the 750cfm it needed, he would get the advertised power.

My car makes about 230hp with the stock tbi's and based on many other peoples setups, should be good for just under 300hp with a slightly built up engine.

My car runs a 14.3, his car runs a 13.6, I know another person who runs 13 flat, and another who just dynoed at 275rwhp and 350rwtq, with tbi setups.

Look at tom400 on this forum, he runs a 13.2

No tbi isnt superior, especially compared to aftermarket tpi setups. But compared to a stock tpi setup, its not that bad if you do it properly. I will defend a tbi setup, because Im well aware of its abilities, i've got the math to backup my claims, as well as the time slips, dyno sheets and observations. What do you have? Word of mouth from a forum? What I absolutley hate is watching terrible advice being thrown around. In the original posters case a stock tpi setup is a complete waste of time, and money, and he will get dissapointing results. Use a miniram or stealth ram!

Visit the prom board, call grumpy out and call him a liar because he has a 325hp tbi car that runs mid 13's.

Im also building up a thread on corvetteforum, full of people who have dealth with this on their own cars. I'll post the link in a little while, but all their data confirms my statements. Feel free to jump in the tell them there all liars too.

Grim Reaper

I have to concur with nsimmons with a "stock TPI". In fact, those that have installed "large tube runners" and ported their plenum still don't make a lot of HP. Torque, yes. HP, no. Generally the HP line becomes as "flat as Kansas" after 4,500 rpm. The dyno charts I've seen with LTRs seem to allow the engine to make the HP at higher RPMs, but it is a "flat line" from 4,500 to max RPM.

To get serious HP, Miniram/LT1, probably the new StealthRam or RamJet and the Superram (though less HP, but more TQ) are the real solution. But, if you start adding up the cost - I would have to say that going carb and putting that spare cash into heads would give much better results.

For serious HP and max bang for the dollar, carb - plain and simple. If you have emission testing to deal with, then you can't even look at a Miniram/LT1, StealthRam or RamJet. To remain emissions legal, the best HP is from a SuperRam.

TPI does have it's place though. I think they make great "torquers", for those that like to tow or run in mud. GM should have kept developing it for trucks.

egmonster

Porting your plenum is a good thing to do, but you can move up the powerband by siameseing the baseplate. You can definately make serious #'s with the stock TPI baseplate and Plenum. Aftermarket runners though are basically a must as the stock runners are well... somewhat on the pathetic side . If you really wanted you could get SLP semi semi siamesed runners and fully siamese them and siamese your baseplate and port your plenum and i'm willing to bet you make some serious HP . You know what would be really nice? If someone figured out exactly how much you move up your powerband for every inch you siamese. That would be a very useful bit of information . Anyway peace.

ir0cz

How is swapping over to TPI then building an engine foolish? Well how bout I build the motor...heads, cam, etc....all with the stock TBI, then swap over to a different fuel injection? Now that would be just down right idiotic...that is why I got the TPI out of the way. And what are you talking about hitting a wall at 300HP w/ the stock TPI? I have 275+ HP right now with stock TPI, stock heads and stock cam.....you're telling me I can't get but 25 more HP out of heads, cam, rockers?

And as for your 400HP stock TPI...you're right....I haven't seen a car w/ STOCK TPI making 400 HP....but if this guy decided to swap to TPI, is he not allowed to get aftermarket parts for it? If you wanna see a 400HP TPI car....look at CHEVY HIGH PERFORMANCE october 2001....they did a buildup on a TPI and ran a 12.3. You show me somebody running that NA w/ TBI. The fastest guy on this board w/ a 305TBI runs a 14.2.

And dont try and claim I dont know what I'm talking about...saying I have no "proof"....if i swapped to TPI, then I've obviously had TBI also...and I know what it's capabilities are. I ran a 14.7 w/ TBI...stock heads, stock cam, stock rockers, stock converter, stock TBI setup....so I know what the hell i'm doing and what i'm talking about. I've owned, tuned and raced both injections, so I think I would know better than you....because all your TPI info is just "word of mouth from a forum" as you stated. Where is your "proof"? And what bad advise has been given? I agreed w/ you that a swap to TPI would be a waste of time in his case...if you would read, I said that if he was planning on swapping heads and cam, it was a good idea, but just for a power gain on his 305, it wasn't a good idea. The only bad advise was you telling him to put a miniram or stealthram on his 305!

And you said that I gained that 20 HP because the TPI outflows the TBI...THAT WAS MY POINT! Why the hell else would I state that? You say you picked up 20 HP from whatever mod you did....well 91rs5speed gained 40 lb/ft of TQ from a straight up swap to TPI on his 305...i haven't gotten mine dynoed yet, but I can tell you that claim is legit....gobs more torque over TBI. Did your little mod get you 40 ft/lbs?

You said your claim of a 325HP wall for TPI is for a STOCK TPI....well is your claim of 300HP for TBI on a STOCK TBI?

ir0cz

You're right....carb is the way to go for straight up POWER. What do you consider serious HP? A TPI w/ runners, manifold, plenum, etc. is good for 350-400HP. That's a butload of HP. Now if when you say "serious", you mean 500+, then you're right, TPI can't cut it....carb or aftermarket FI is the way to go. And besides, all this talk of TPI not making much HP, but lots of torque is bull.....torque is what moves the car. We dont drive hondas.....we actually HAVE and USE torque.

nsimmons

good points glenn,

eggmonster, ive done the math, alot of it, and it works out to about 2.5% of the runner removed moves the torque up about 100rpm, now im talking from the plenum to the intake valve, so thats about 0.65" for every 100rpm. Now this is pure theory and i couldnt test it without alot of cutting and grinding and dyno time, bput you get an idea.

irocZ, i'll only address a couple of your points, because no one agrees with you, and i grow tired of your blathering.

Again you just state tpi with runners plenum, base can make 350-400hp, THATS NOT STOCK!! please clue in here STOCK STOCK STOCK. No cutting no grinding, no polishing. STOCK!!!

First I didnt say theres a wall of 300hp with tpi, if i did its a typo, on average, around 325-335 is the practicle limit for stock tpi, unless you get really insane with the motor. No Im not saying you'll only get 25, you'll get about 50, and probably torque in the upper 300 range, but not hp in the upper 300's. You asked if the guy swaps to tpi, is he not allowed to buy aftermarket part?
Thats what I advised!! What i told him was do not swap to a stock tpi, then spend another grand to swap to an aftermarket setup. That is a waste of money and effort.

Second, you cant seem to grasp the concept between tpi and point injection. Once you install a super ram, or a stealth ram or a miniram it is no longer tpi anymore, it is still a point injection system but it is not tpi. TPI=tuned port injection. The runners are nolonger harmonically tuned with a miniram. Hence it is no longer tpi. Im well aware of many many low 12 second/high 11's gm cars running 350's with gm point injection, but none of them are running tpi anymore. You then compare a car probably running a very hot 350 with an aftermarket setup to a weak 305 with a gm setup..good job apples to apples right?

Third, you keep comparing tbi to after market injection setups, why? Im not, its clear the aftermarket setups are vastly superior. Im comparing tbi to tpi, your comparing tbi to third party setups specifically designed for power. TBI in nature isnt bad, holley makes tbi setups that flow enough to make 700hp. Its just rochester tbi wasnt designed for performance.

Fourth, you say you ran a 14.7 with stock cam, heads, stock converter, stock injection and claim to know its capabilities. Total crap! You didnt max out the system, you didnt attempt to reach a goal and fail, you just assumed the tbi was bad and tossed it. This shows that you dont have any experience with modifying one. If you had built up a nice engine, under the stock tpi and 14 flat, then you would know its limits, and could decide whether or not to modify the tbi or swap to something else.

Fifth, if you were paying attention he's installing a 400, not a 305 like i said in another post, a 400 will have plenty of torque so i would op't for a miniram over a super ram, but you knew that didnt you.

You claim you have more experience racing tbi and tpi, how do you know that, ive owned, moddified and raced 3 tpi cars, 2 tbi's and assortment of carbed vehicles.

My little mod as you so called it did add hp and torque, and since i have 330ftlb on tap now, it runs identilce times to an 85 vette, which has the same engine just with tpi, and besides i can still work you in a race, with lowly tbi.

What would you say if i told you a lowly tbi car I know out ran a viper with out juice. Just a properly modded engine. Common sense, well planned mods.

You ask for proof, what proof do you want? I have time slips, dyno sheets, flow bench numbers. My statements comes from a vast amount of exposure, yours come from you racing a relativly stock 305.

My claim of 300hp stands for a stock tbi, with some latitude of course, monster compression ratios and strokers change things.
My friends car makes 306hp as I stated, with a 355hp engine, the intake isnt the restriction neither is the exhaust. The only thing left is the 550cfm tbis, as such about 300hp is the limit. Thats simple deductive reasoning.

btw heres the other thread i started, your wrong there too.
http://forums.corvetteforum.com/zerothread?id=330753

Grim Reaper

I have seen a lot of guys post their dyno runs using variations of the TPI system. Until you start going to siamesed runners (with heavily ported base), the HP of those engines are severely limited. TONS of TQ. AND they DO BREATHE enough to make HP AFTER 4,500 rpm - BUT it's a FLAT LINE. That's IF you remain with the single runner system. Only siamesing will allow more HP in the 5,000+ range, but it too "flat lines" fairly quickly.

I think Tim Sifford (Traxion) had Siamese runners using AFRs and a good cam (230/236) he couldn't get 300 HP at the rear wheels until he went Miniram. He's posted a copy of his Dyno run somewhere on this website cause I remember how ecstatic he was when he installed the Miniram and finally getting some real HP.

Yes, you will get SOME extra HP with TPI and GOOD HEADS, but ... what a waste of a good set of heads. If I was too spend my hard earned dough on a nice set of AFR 195s, I would want an intake that could take full advantage of those heads. And TPI is not it.

But check around...there is HARD PROOF with some dyno runs by Tim if someone does some 'checking'. I don't need convincing, but those that do should look for them.

Also look for some dyno runs from "GregWestphal" (I think). I think he had a fairly built motor with LTRs. He couldn't get more than 260 RWHP - but it was 260 RWHP from 4,500 rpm to 6,000 rpm.

iroc22

Uh oh.....

It's foolish because you will end up spending more money. I don't know, sometimes I like to throw my money into the fireplace. It's amazingly logical to do a swap from the low end fuel injection to the high end in two steps; instead of going low to mid to high. It just doesn't make sense.
Uh with the whole 'barrier' thing, he's actually referring to the TPI setup, not the heads, cam and rockers. You don't know about the barrier, because you're not at the barrier yet. Makes sense doesn't it?


Haha this is hilarious. Do you realize that if he installs aftermarket parts on his stock TPI setup, then it's not stock? and that completely derails the arguement of a stock TPI setup not being able to surpass 325hp? Oh I have that issue of CHP. Yeah that's a fair comparison. 305TBI to a 350TPI with tons of cash invested.

There's no way on this earth that you ran 14.7 with all those stock parts on a 305TBI. I'd love to see a timeslip. Yeah and such bad advise was given because the stealthram and miniram are such horrible setups

That's on a mild engine. The original poster of this thread is not putting this on his completely stock 305. Wow you made 20hp and tons more torque on the dyno? Oh wait you haven't dyno'd it yet?......

Yes actually it is, if you read his post.

ir0cz

There would be no arguement here if you would read a little closer....

first, yes, i did say that a souped up TPI can make 350-400 HP....but I made it clear that a STOCK TPI could not...STOCK STOCK STOCK. I made that clear.

And what do you mean I cannot grasp the difference between TPI and point injection? I have not at any point compared the 2 to each other. When I say "aftermarket TPI setup...I am refering to TPI w/ runners, plenum, manifold, I'm not talking about miniram, superram, etc.

And as for my 14.7 w/ TBI...did I say that I KNOW it's capabilities? I was actually telling you that to let you know that I KNOW TBI is no sloutch. If I ran a 14.7 w/ TBI and all those stock parts, then TBI must be able to handle it...THAT was my point...i was backing you up by saying that. And because I tossed the TBI doesn't mean I dont know how to modify one....i modded it plenty...it simply means I like TPI better, so i swapped to TPI.

As for racing experience...i DID not say I have more experience than you....you could be John Force for all I know...I was stating that to let you know that I've owned TBI and TPI and have experience w/ both. But nowhere did i compare my experience to yours...becaue quite frankly, i know nothing about you, so i cannot make a statement like that.

And it's funny that i'm racing a "relatively stock 305" when I yanked the 305 over a year ago. The reason I'm not running much quicker than I am (i haven't run since swap to TPI, but guessing about a 14.5) is because my 350 crate motor is under warranty...so i dont wanna get into it till warranty is up.

And why do you keep recommending aftermarket setups when he's running a 305. Yes, he's building a 400, but he's asking if he'll get any benefit from swapping to TPI on his 305...at least that's what I understand his question to be. It'd be different if he had a 350...he could put the aftermarket setup on the 350, then it would swap right over to the 400...it's not as easily done w/ a 305

The whole problem here is that you're not reading my statements closely enough...you're missunderstanding them I guess. As for your statements about 325 for TPI and 305 for TBI....i dont totally disagree w/ you...i think STOCK TPI can make up to about 340. What I dont agree w/ it TBI...you say a STOCK TBI can make up to 300 HP....anyone I"ve ever seen making anywhere around that has modded the TBI or gone to aftermarket TBI. I dont think all this arguement is necessary over me disagreeing w/ one statement you made. I say we get back on the topic and end this.

On the topic. I think that a straight up swap from TBI to TPI on your 305 would be a waste of time. The TBI will be able to handle the power of your 305 until you throw in the 400. And as for the 400...i'd go w/ carb, but if you want FI, then I'd go w/ an aftermarket setup, because if you went w/ TPI, by the time you bought the TPI setup, everything for the swap, runners, plenum manifold..it'd end up costing more than a superram or such. good luck.

rockind78

nsimmons,

You have actually pretty much said everything I would have, with exception to above. The Stealth Ram and the Super Ram are Tuned, its just for a different RPM range (just like the LS-1). Check these out.

http://www.chevytalk.org/forums/Foru...ML/000649.html

www.bgsoflex.com/intakeln.html

You will see that it is possible to maintain a "tuning" or "ramming" effect with different length runners.

RedFirebird

Toilet Bowl Injection

Anything else is worth when you have TBI. Dump it. I'd definately opt for TPI or someother variation of it. And there are tons of used TPI parts out that you can get for very cheap. Hell, throw a carb on there for all i care. A 400 will not do well with TBI sitting on top of it (or anything else meant to make power).

ir0cz

It's not foolish if you are going for a reasonable amount of HP. On this motor, I'm looking to get 350+ HP w/out having to go to something other than TPI. Now if I was planning on making it an 11 second car, then it would be foolish to swap from TBI to TPI to superram, but I'm not, so I dont need anything bigger than TPI. And in this guy's case, it wouldn't be stupid to swap to TPI BEFORE he builds the motor because he's not gonna get an insane amount of power (it's a 305), so TPI would be plenty. Should he put on heads and cam as he wants, and then take care of the induction? No. He needs to get as much out of the setup he has now before he makes it more powerful. And as for the barrier...i know he was refering to the TPI setup, my point is that if I make lets say 290HP right now....and the barrier for a stock TPI setup is 325 HP....then if I put on heads, cam, rockers, better headers, and whatever, then I'll only pick up 35 HP because the stock TPI setup will restrict it?



Look...I made it clear that a car isn't gonna make 400HP w/ a STOCK TPI setup...I made that clear. But somebody said they'd never seen a 400HP TPI PERIOD, so I put that in there. It served no purpose on the arguement...just to show that it's possible w/ TPI. I made clear that a STOCK TPI setup could not do that.



If you would look at the sig...i'm running a 350. 14.7 w/ a 350TBI. And as for the bad advise...it is bad advise for the guy to tell him to put stealthram or miniram on a 305! It's not like he has a 350 where he can put on stealthram and swap in onto the 400 when he's done.....it's a 305...there'd be no point in putting on stealthram or miniram...that was the bad advise given.



Whats your point? I stated that i picked up some HP from a straight up swap...just to prove how much better TPI flows...and you're right, I dont know how much TQ i picked up, that's why i didn't pull some number out of my *** and say "i picked up 50 lb/ft" But there is another guy on here (91rs5speed or something like that) who DID get to dyno after a swap from TBI to TPI on his stock 305, and he picked up 10RWHP, and 40lb/ft at the wheels.

Ya know, i used to have some bit of respect for you because you gave relatively good advise...but now I know you're just another ******* that thinks he knows it all.

rich88gta

Is it just me? Does anyone else feel like they are in the middle of an argument between thier parents? Agree to disagree....lets move on.

If you still plan on getting new heads and a cam then I would say yes...go with the TPI. Search the boneyards(or maybe Ebay) around your area. I am sure you can pick up a complete TPI setup for a minimal amount of $. The gains you would see IMO would well be worth the couple of hundred bucks and time that it would take to do the swap.

Flame on

ir0cz

The norm for TPI setups w/ harness, computer and all is about $400-$500. But then you gotta get fuel pump, cables, and other little odds and ends. Comes out to about $700+ and that's if you can do it all yourself...no labor. Of course everyone gets lucky sometime and scores great deals. Oh, and trust me....a flame war IS NOT what I wanted..but some people just get mad when you disagree w/ them ya know? later...

iroc22

Read your first post. It was an intentional flame. It nit-picked everything that nsimmons said. I did the same to you and you raised your back. You don't have any basis for your arguements, nsimmons and Glenn do; they've seen it all and have experience to back up what they say. You disagree with them, and claim that what you are saying is the right way of doing things. I'm just saying listen to the people that have experience with these things. Read Glenn's last post really carefully. These guys have experience with the hp barrier with these systems. You're not there yet. Just read dude.

ZZsmpch

iTrader: (1)

Waaaaa, I want my bottle, waaaaaaa. What was the question again? BTW, I think you're all wrong. He needs a 502 BB with an 8:71

ir0cz

You're right...my first post was a bit rough, but it was not meant as a flame. How do I have no basis for my arguments....I really only diagreed about the amount of HP a stock TPI can handle....and I thought it was like 15 HP higher than what he said...so no big arguement there. The real argument lies in the what this guy should go about things. This is a matter of opinon....and my opinion differs from Nsimmons....so how does that make me wrong? I may not have experience w/ TPI's HP barrier, but I do have experince w/ TBI, TPI, and carb...so I think I have something to base my OPINION on. You say that i disagree w/ them and clam that what I say is the right way of doing things? Well what's to say their way is the RIGHT way? This is all a matter of opinion....if we think he should stay w/ TPI, go to TBI, etc...and I'm the bad guy because my opinion differs? Not quite. Once again, I'm sorry I started the flaming....but I also keep trying to end it....to no prevail. Oh, and you said to listen to the guys that have experience with this.....and they have more experince w/ the HP barrier than me....so I'll back down and take their word for it...but as far as the question at hand...i DO have plenty of experience, so I think that intitles me to a voice. He asked if he should stay w/ TBI of swap to TPI, well i've done that swap..paid the money, did the labor, got the results...so I think that I have enough knowledge about the subject to give a respectable answer.

Ed Maher

This thread is just stupid. If trying really really hard just to maybe run in the 13s is your bag, then by all means beat yourself up trying to make TBI work.
Is stock TPI the end all be all of manifold design. Quite the contrary, it's a horrible design for making power. Which makes it's ability to handily outperform anything TBI just that much more impressive (or sad for the TBI, can't decide if the glass is half empty or half full.)

I'm closing this thread because it's pointless. As a 'comparison' thread this is just going nowhere. I personally try not to take performance advice from 350 vettes that would lose to naturally aspirated 305s.

So in closing, a final test...
If you want to see the difference in performance potential of TPI vs. TBI, start 2 troll accounts and post 2 threads, one to this board and one to the TBI board with a basic combo and report a modest timeslp for it like say 13.5 @ 102. You'll be the stuff of legends for such a feat with a TBI car. Just another day at the office on a TPI board.
Or even better yet. Take a gander at how many modded/swapped 350 TBI cars there are running mid-high 14s!!!!!!! Oh sure, the occasional carb or port injection swap can come out not quite right too. But with TBI cars, it's the rule, not the exception.