I am running a converted LT1 intake on an a gen I SBC set of heads. I came across a set of vortec heads for cheap that I want to try on my truck with a stock TPI intake. Has anyone re-drilled the vortec heads to fit the TPI base? Was there enough material on the TPI base to port match the higher vortec ports, or did you have to weld the TPI base ports?
I know there is a vortec TPI base available, but I want to stick with the free TPI base I have.

 

The Vortec heads can be re-drilled for the old style SBC intake bolt pattern, but it is NOT recommended as you run a very high risk of hitting a cooling passage. Scoggin-Dickey sells their own casting of modified Vortec heads that they modified the casting of to incorporate both the Vortec and old style intake bolt locations on, as well as both perimeter style and centerbolt valve covers. Both Edelbrock and Scoggin-Dickey offer Vortec pattern high-flow TPI lowers, for around $400 each. The stock TPI lower CAN NOT be modified to fit the Vortec bolt pattern.
If you want to risk drilling the old style SBC holes in the heads, take them to a machine shop, and discuss with them the pros and cons of the mod. Ask if they've successfully done it before, or are familiar enough with the Vortecs to attempt it. I asked Kendrick Performance about modifying my Vortec heads for the same reason you're looking at, but they recommended strongly against having it done for the same reasons I've given.
The other consideration is that the Vortec TPI lowers give you much improved flow over the OEM lower, often an overlooked item when people modify their TPI systems or port the upper plenum or runners. Replacing the lower with the high flow is a significant investment, but with the gain the Vortec heads provide and the higher horsepower support you gain are well worth the expense.

 

The stock TPI heads have intake bolts going into the coolant passages. Why is it a problem with the vortec heads? My main concern is having enough port material and needing to weld the ports. Was there enough port material?
I could always weld the intake to make the 8 bolt holes and leave the heads alone, but the port material is my main concern.

 

No TPI Heads DO NOT have bolts going into coolant passages.

The outer ones are blind. The inner ones go into the crankcase.

This proposal is not a good idea, for all of the above reasons, and more. I suggest that if you are REALLY interested in the Vortec heads, you ditch TPI altogether since it defeats the very advantage that those heads offer; and put something with some degree of performance potential on it instead.

For what you'll end up spending dinking around with a bunch of TPI crap that will retain all the features that keep it slow, you could buy a Stealth Ram. That's probably a wiser course of action.

Sometimes "free" is more expensive than "buying" something. This would be one of those cases.

 

I have a set of vortec heads that I got a friend that has milling machine to re-drill for me. Worked like a charm. Use a Felpro 1205 gasket, but the TPI intake has to have about 1/4" welded to the top and then portmatched. I did it and then had second thoughts and used a Miniram III that is set up for fastburn heads. It matched the vortecs fine using the re-drill and 1205 gaskets.

 

I just don't understand how heads with excellent drivability due to velocity in the port design don't just magically match perfectly with the worst possible intake manifold produced in 35+ years. What if the parts were like a really good deal and / or they were already in hand. Would that make it a better idea?

I knew you'd come around and explain.

 

You are right about the water passage bolt holes. I don't know what I was thinking on that one. The intent for the engine is to try to make peak torque around 3000-3500 rpm and maximum fuel efficiency. Along with that will be a small cam. It seems that the vortec heads and TPI would work well together for this type of setup. Is there a better intake that would make more torque around 3500 rpm? Peak HP is a don't care for this engine.

 

Just buy a vortec intake for tpi. Stright bolt on. I was going that way on my engine. But never did it.

 

Vortec heads, and all of the welding and drilling and who knows what else to graunch them together with TPI, offer NO BENEFIT for the situation you are contemplating. All they off is a GIANT maze with not even a crumb of cheeeeeeze, but instead nothing but a mousetrap, at the end.

Even buying the TPI Vortec base would be a complete waste of money. There's nothing that it, plus the Vortec heads, will do, that some other heads won't do just as well with the stock base. Big expense, no payoff. See "maze" and "cheeeze".

For an engine that's designed and intended to be all done by 3500 RPM, TPI is perfect. I wouldn't change that, if that's the design goal. I'd suggest using heads that fit it instead of Vortecs. Buy em cheeep, sell em dear, and use the money to get something that's actually APPROPRIATE. Which might even include something as unromantic as 305 heads.

 

 

Thank you for the pic Vetteoz. It looks like more welding work than I wanted to do. I think I will just convert a Vortec carb intake to EFI.

 

Yeah, It took my welder buddy almost 4 hours to build my TPI intake up and it took me about another 4 hours to port back out to match 1205 gasket. It just didn't like the look of that big ole port going into that little intake, and I bought me a Miniram III.

 

I got a free dual plane vortec pattern intake with the heads. I haven't decided if I want to convert that or just get a single plane vortec to convert. I have the TB, fuel rails, press. reg.

The engine is a 9.0:1 comp ratio, vortec heads, 218/218/110 cam, 75mm TB, twin 50 trim T3s, and not sure on the intake as of yet.

I was going to go with a smaller cam, but I got the one listed above for next to nothing brand new.

 

I have a set of patriot vortecs with dual bolt patterns here are some pics and a video of intake fitment and gaskets

https://www.thirdgen.org/forums/tech...eads-pics.html

OK here are some pics of a non vortec gasket. What I found is the gaskets that came with the kit will seal either manifold no prob the gasket part number is

http://www.jegs.com/i/JEGS+Performan...10003/10002/-1

So I put a non vortec gasket over my heads note the gap. Please watch the video









VIDEO

 

Those are some good pictures. How does that JEGS gasket work without any intake material backing it up? What happens if an intake port fires back through the intake with a non-vortec manifold? Or using boost with the intake valve closed? Is there steel in the gaskets to try and add strength? I think all gaskets need something backing them and I don't see how that one seals with an intake portion covering it.

 

I was bored the other night so I fired up the TIG and welded the stock GM TPI intake to fit the vortec heads. Now I am moving on to drilling the heads for the early TPI bolt pattern.

Has anyone done the hole drilling before? I am going to drill the holes for 3/8" fine thread bolts. The problem is the outer most holes. I used some wire stuck in through the coolant holes and there is not enough material there to drill a 21/64" hole for the 3/8" tap. It looks like I can get away with a 5/16" bolt and not punch through into the coolant port. There simply isn't enough casting towards the lower portion to use a 3/8" and not end up in the water port. I am only drilling the hole the depth of the casting which will end up with a hole about 1/2" to 3/4" deep.

Is it just some 906 vortecs that have limited casting material there? Has only one drilled for a 3/8" bolt?

 

i have a l31 with a tpi on top,and it destroys l98s and lt1's.it pulls hard all the way to 5k,the power range of the tpi and l31 compliment each other perfect.you keep knocking the combo,but look at the numbers sdpc and edlebrock made and i think even car craft and hot rod magazine did the swap and made good hp.how can you say no benefit?dyno's have shown it.

 

My 1987 Iroc-z with a L31 vortec makes my 89 iroc-z L98 look like a mopad comin off the line....so i do see alot of bnefits and even eats my bros 1992 Z....with hooker headers on vortec heads sounds mean as well...now i got lucky and got all my set-up for $200 brand new from a lady when her husband died wit a 3k mile motor

 

what those people dont tell you is that those manifold's had work done to them...people will say anything to sell the product but thats not the real world case... The fact of the matter is that the vortec baseplate is ONE OF THE WORST flowing aftermarket tpi bases in stock form.. weather you like it or not thats the truth. its only a tad bit better than the stock base...

Your MUCH better off sticking with a non vortec aftermarket tpi base (but still the gains are not all that great unless you do some work on the manifold) and even at that the base is not compatible with the higher flowing vortec heads so either way your going to have to spend money somewhere...because build would be a vortec heads and a FIRST intake with the vortec style base.. ... Ive done it all.... with bases runners and plenums... was not happy with performance then i moved onto the FIRST and was a happy customer ever since....

Imo its not worth all the trouble to try to fit that stock base on vortec heads because im telling you that you WILL be upset with all your efforts.. you take a stock base and sit it right next to a vortec base and you tell me which one is the "performance" intake....

the heads are great... dont bottleneck those heads with a hack job stock tpi base on them and expect it to run great.... its just not going to happen... either get a hsr or FIRST imo... cause like sofakingdom says you may think your saving money now but its going to cost you money and alot of unwanted time in the long run....

 

Wow, you two sure are fast with your TPI intakes. Do you guys have problems with popping wheelies? Let em rip!

After some reading it appears that drilling the end 4 bolt holes without breaking into the water jackets is impossible using 3/8" bolts.

 

lmao, thanks for letting me know how I am going to feel. How long does it take you to do the welding and machine work? How do you know how long it takes someone else to do it? Are you a machinist?
Not to worry. I am also drilling an LT1 intake to fit the vortec heads so I can do a comparison of what curve I like better. I have an HSR in a box and they don't really impress me. FIRST is expensive junk with excellent marketing.

This thread is full of opinions of intakes. I think only 1 person actually provided help about doing the conversion. Everyone else just wants to brag about what intake they have or why X is better than Y. You guys sure know a lot about what works and what doesn't without even knowing anything about the intended use of the engine.

 

hey i didnt mean any harm... i just saying that it wasnt worth it... i wasnt trying to bash you only try to tell you that for all the trouble its worth and risk of drilling an intake like that for vortec heads and crossing your fingers hoping it works just isnt worth it....

for the record the FIRST is not junk... since you want to get technical..... my base flows 301 cfm untouched and around 290 cfm with the runners attached... thats better than a hsr and a superram out the box.... so its not marketed crap...you have to port and weld a aftermarket tpi base to even reach those numbers..... so my junk is FAR better than what your tpi can ever provide....

 

i dont care what base flows what over the stock one.

i used the edelbrock base

let me bottom line it:my stock L31 with tpi will destroy a stock L98 tpi, period,thats all i wanted,not looking to run 10 second 1/4 miles,i needed a motor and this is what i selected and it makes more power than these cars ever came with,and its within the limitations of the rest of the drivetrain.

everything could always be faster with this,that and whatever you bolt on. but to tell people there is no gain with vortec tpi is b.s.

 

I have a (I never installed it due to me getting a T-ram) used gasket matched SD TPI vortec base and 1 NIB GM Fastburn head forsale. I have 1100$ in it. open to offers. sorry no lowballn .. my ole lady knows what I spent and wants it back .. lol
PM me if interested.

 

Yes, to some it may not seem worth it, but it really depends on the application.

I went over board saying the FIRST is junk, but I still stick by it being expensive for the performance it gives. Please post completely assembled intake flow numbers for the HSR, LT1/Miniram, and FIRST TPI if you have them. I would be amazed to see that any manufacturer long tube will out flow the HSR and Miniram runners.

 

Putting on vortec heads on an L98 would give gains.

 

I think they have a forum for selling parts. You might have better luck trying to sell it there as there would be more viewers. Good luck.
My ole lady would kill me if I spent $1100 on a set of heads and intake when she knows I have $1500 into the turbo setup that makes an additional 180HP with the stock engine.

 

my car walks on l98 cars,no payoff....? sure

waste of money?....... i paid $200 for the truck my L31 was in and drove it home.


i know that....... but some other people still disagree

 

Yup I know they do. I have it posted there also.
Sad part is thats only 1 head and the TPI base..
Just think, if you added heads and a higher flowing intake set up you could make more power on less boost!

 

I keep seeing so much vitriol directed on these forums against the TPI, and much of it seems to come from misinformation and ignorance. This is especially evident everytime someone says "worst intake ever designed" or anything along those lines when refering to tuned port induction. Some points of interest to keep in mind when discussing the TPI;
1. The Stealth Ram, Superram, Ramjet 502, LT1/LT4, and even the LS intakes are ALL tuned port induction systems. They all use individual tuned length runners with port induction. Saying they are not is the same as trying to say a Quadrajet is something different than just a carburetor.
2. The stock TPI was designed to feed the Chevrolet 305 ci V8. It does this remarkably well throughout the power band, especially considering at the time it was a quantum leap ahead of its contemporaries.
Remember that in the early 80's when it was developed carburetion was still rampant and TBI was the norm for most production vehicles. The LT1 that is so often suggested as a step up from the TPI works better in the upper RPM ranges because its runner length was developed specifically for the Chevrolet 350, unlike the TPI. It also sacrifices bottom end torque to achieve this, and this must be noted. The TPI in stock form cannot feed larger displacements in the upper RPM range, because it was never meant to. This is not to say that modifications cannot be done to alleviate the issue. I've noticed that most of the people directing hatred towards the TPI are using 355's, 383's, etc. This would be like complaining about a poorly performing 383 fed by a 2-barrel 500cfm carb, or conversely a dual quad carb setup on a 305. Proper setup for the proper application.
This also goes into head selection. A lot of people will try to use massive intake runners with a TPI setup, then complain about less than stellar realized performance. While larger volume would usually give power gains, such as on a carbed setup, you must also remember that higher port velocities from smaller runners can lead to increased performance. It is possible to feed too much volume at too low a velocity and kill performance. Basically, the 3/4 rule must be obeyed. Again, engine displacement plays a big role in this, as does valve size and cam specs.
No, the TPI is not the best system ever developed. However, it is a very good one when properly utilized, especially for a budget builder.

 

I had to add material to the top of the intake ports and the water ports. Just a little clean up on the top of the intake ports to match the gaskets and it is ready to go. It took about 4 hrs to weld and grind. The 1.5hrs of port the intake runners to get a vortec runner port match.

 

^ looks awesome good luck man

 

Right. Any design of intake manifold for fuel-injection that was put into mass production and pass emissions is "tuned" in some capacity.

The issue in a nutshell is that TPI is the longest dedicated runner length (i.e. no dual-runner designs considered) used on any engine intake manifold.

A Q-jet flows more than some carbs and less than others. It also has small primaries for good low-rpm velocity and big secondaries to flow high-rpm. And it had some limiting factors (secondary air door stop tabs) which are comparably easy to modify or change than reworking or designing a whole new intake manifold.

So not only is it a major limiting factor for an engine series with far more rpm potential, it's also fairly costly or complicated to change.

Irrelevant. It's runner length that is at issue moreso than absolute flow. And GM knew full well they were potentially running it on a 350 and they ran it without port changes for 8 models years.

Runner length is what screws powerband.

Most people with 305s at least consider changing the whole engine out and aren't worried about modding it significantly.

I have had an L69 stock, and w/ a Q-jet and cammed, w/ TPI and cammed, and w/ TPI and stock cam. If I knew then what I know now, I'd have put headers on it, kept the ZZ4 intake and Q-jet and left it alone so that it would run hard to 6000, not choke at 4800 and walk all over TPI engines. I don't hate the batch fire or any other limitations of the ECM system. It's really just the intake that limits a good system.

 

It depends what engine characteristics one is after. I am looking for max torque, not max HP. The TPI runner length was designed for pulling not revving.

 

I did consider converting the dual plane carb vortec intake into a MPFI setup. The thing that made me decide not to was possible fuel distribution problems and having a few lean holes under boost. The ECM has two drivers so I thought of putting 4 injectors on the short runners and 4 on the long runners and tune each driver according to plug cuts. In the end, I decide to give the TPI a shot. If I don't like it I may try the LT1 intake or convert the dual plane intake. I want to make the most torque I can at the lowest rpm possible so the LT1 intake is kind of out.

Do you think the dual plane would make more torque than the TPI?

 

Another option, lt4 intake ports line up with vortec ports. You can weld onto the intake to match the vortec bolt pattern. The vortec heads make awesome torque even with short runners. And the lt4 intake will rev over 6k.

 

The LT1 intake I have matches the vortec intake ports. I would just need to add the front coolant ports and drill the bolt pattern. I am running EDIS with it so the distributor is not needed. I will probably set this intake up for the vortec heads since they are off the engine.

 

junkcltr I sent you a PM. I have a brand new pair of EQ lightning vortec heads that are drilled for gen 1 only ($99/each close out specials on ebay a while ago) that I wanted to use with a TPI base. I would be interested in paying you to weld and grind one of my spare TPI bases if you have the time.

 

Lots of interesting opinions. They're all right. AND all wrong. There are so many factors that go into the selection of engine parts, and nobody can know what someone else has planned without discussing it. Maybe budget is a factor. Maybe the TPI looks cool, and they don't wanna change. Maybe it's a tow or truck motor. All we can do is try to educate each other as to what parts will and will NOT do.

I remember at one point scoggin dickey was selling a set of vortec heads, the TPI baseplate and a cam for well under $2000. For the average guy with a stock L98, not looking to do constantly be tinkering under the hood, this combo, at this price, all from one location is an awesome kit. It's not intended to be the next quarter mile king. Same fuel rails, same injectors, same sensors, heck even the same tune on MAF cars. It's not intended for those of us who scrutinize air/fuel tables looking for 2 more horsepower. But at the same time, those who choose this route, or similar vortec TPI routes need to understand that just because you love the increase in power, and it'll walk a stock L98 for days, it is by NO MEANS the most efficient, and most cost effective option out there. NO part of this combo can be used to build larger, higher power builds in the future. The manifold barely outflows the stock one, and even the valvetrain needs replacing if you want a larger cam in the future. Quite frankly, it's hard to recommend this combo to anyone! Two completely different takes on the same combo. it's ALL RELATIVE. Ya have to understand who you're talking to.

 

So what should I be expecting for my 350 L31 Vortec, SDPC intake manifold, stock runners/plenum, throttle body, K&N dual snorkel cold air intake, 1.6 roller rocker LT4 hotcam, shorty headers, 3" hollow cat American thunder exhaust, 24 ilb injector, custom tune ECM, no emissions, and MAF set up? I'm ordering the rest of the valvetrain hopefully two weeks from now...

I'm going for at least 365hp and 425 ft/ilbs here fellas....I think its realistic(considering a stock L98 makes 245hp and 355 ft/ilbs)

 

Which ECM? Maybe I missed it.

Peak torque at 3500 & mileage...

Power under the curve w/ boost means you should be focusing on exhaust above all else. The velocity gains of having a mega-long runner intake are lessened when using boost.

Might you make more peak torque @ 3500 w/ a TPI intake over a dual-plane w/ injectors? Sure but either one is a compromise. The TPI intake is going to start hurting power above 3500 and the dual-plane isn't going to help anything on an EFI engine over a single plane.

In the interest of overall power, including that in higher rpm ranges, I'd consider the right DP4bblEFI intake w/ the divider knocked down or preferably a SP4bblEFI intake.

No matter what peak you're aiming for, going for the longest runner intake w/ boost means you're mis-matching the overall engine. But I can appreciate the forging of untraveled ground, so to speak.