slowmaro87

ok ive been searchin for days trying to find my situation buut not having too much luck ...i have a 89iroc 305 tpi that im wanting to swap my newly purchased 1995 350tbi into but im not sure if i want to buy an intake carb distibutor sending unit all that good stuff for a carb setup ooor try to get my tpi setup to work for the350 wich would be great ..my question is ,,wich would be the cheaper route and what all would i need to convert the 350 to tpi considering i have most everythingfor my 305 tpi to run...

five7kid

iTrader: (14)

Install the 350 with your 305 TPI hardware. You should use the 350 knock sensor (hopefully still installed on your engine) and get a 350 knock sensor module for it. The factory used 19 lb injectors for 305's and 22 lb injectors for 350's, but it's not like the 350 won't run with the 19's. All of the rest of the TPI hardware is identical between 305's and 350's. You should be able to find good used 22 or 24 lb injectors.

Putting your 305 cam into the 350 would be a slight improvement (roller vs. flat tappet, mainly). Your 305 heads on the 350 would be even better, but not sure you want to go through that extra work.

It would run better with a 350 chip or custom tune, but like the injectors, it's not like it won't run with the 305 tune.

All of that would be cheaper (and arguably easier) than putting a carb on the 350.

slowmaro87

thank you very much for the reply ...what kind of work would i be looking at to put the 305 heads on the 350 ?..and would it still run on pump gas? i would figure raised compression with that setup hmmm..and when looking for injectors at pull-a-part what kinda cars would you think i should checkout ...wouldnt injectors if all same lb be pretty universal from make and model and how would i know how many lb they are?..oooor would it be easier to just buy ebay injectors?..as far as cam iwas thinking of going with an aftermarket wouldnt mind suggestions for this setup (realy want some sound but still drivable i know its alot of questions but if you (or ne 1 for that matter lol)dont mind sharing knowledge id be very happy to listen lol...1 more thing where is the knock module located..again thank you so much for the reply

s10irocspikes

I have to disagree with going with TPI as easier or cheaper in the long run. Not only is anything not cheap for EFI, (injectors, throttle body, intake) but you'll have to invest even more time and money into tuning, either the setup to do it yourself or the price to have a shop do the tuning.

Trust me, it's a hell of a lot easier to tune a carb. Also a carbed setup will cost about a third as much as a EFI setup.

slowmaro87

i am now leaning more towards the tpi setup along with the other questions i have stated ..what size injectors would you guys go with the 22 or 24..with possibly using the 305 heads and cam..i am thinking of doing some work to my heads also weather i use the 350 or 305 heads im not sure ...as you guys can tell this whole engine build is up in the air...any answers questions comments are greeeatly appiciated thanks again guys

five7kid

iTrader: (14)

spikes, he already has the TPI set-up. No mention was made of a desire for performance upgrades other than the 350. Buying new carb conversion parts would be much more expensive than the gaskets and knock sensor module required to put the TPI on a 350 shortblock.

Tuning EFI is a matter of keystrokes (after you get the chip burning equipment). Can't say that about carb. EFI gives you data, carb is a guessing game (unless you want to talk about the expense of getting wideband O2 or EGT equipment). However, not likely you'd need any special TPI tuning for this swap.

EFI will always be superior to carb for driveability and fuel economy.

Yes, it would run on pump gas. The 305 heads have smaller combustion chambers, but the 350 TBI has dished pistons.

The knock sensor module is on the firewall in the back driver side corner.

s10irocspikes

I guess I got confused. Camaro + 350 = not for performance?

Anyhoo, like five7 said about the knock sensor and module is spot on.

I myself am kinda skeptical about spending $120 on head gaskets to swap heads for minimal performance gain and time doing so. If you're gonna pull off heads, at least do it for Vortecs or better. But then again, you're already pusing the envelope for custom PROM tuning with the motor swap alone.

I would recommend a cam swap cause the TBI cam is useless. If the lifter valley is drilled and tapped for the hold down tray for roller then install your roller and components out of your 305. If not, your call. Remember to install the lifters in the EXACT same direction and position as they came out of the 305 or you could wipe out a lobe or 2 on your cam. Again, more time wasted for minimal performance gain.

My opinion, save the roller components for when you're ready to drop some coin for real performance. Integras and Civics come out of the factory with 170hp, about the same as a stock TBI 305. $ave up.

ALSO, I SHOULD HAVE MENTIONED FIRST, watch how big of a cam you go or you'll overpower your valve springs. (Valve Float- Where your valve springs can't keep up with the larger lifting cam and your lifter actually jumps the cam lobe like a dirt bike) Here we go with money and power again.

You know what, scratch that. Grab a set of stamped, roller tip, 1.6 ratio rockers and install them. You'll get .030 more lift and a little more duration with your stock cam and you don't have to worry about overpowering your springs. Just a simple rocker swap, cheap, lil mo powa, and you're done.

Save your time and money for when you're ready to get into performance cause everything is going to conflict with each other if you do it one thing at a time, starting with the PROM. It will be your best friend and worst enemy. Someone else will have to tell you about tuning cause I HATE IT. Ill leave it at that.

The 19lb injectors will work for now with your current setup. Mainly because it's what your PROM is programmed for. Just get an adjustable fuel pressure regulator and add more fuel pressure.

Get the 350 knock sensor and ESC module, drop in the motor, put your intake and rockers on (gaskets), install a AFPR, fire it up!



That's about it for now. Good luck and post up Q's and probs. We're here to help.

slowmaro87

ok so a couple of months went by and the project has changed a bit now i have decided to go the carbed route the 350 is at the machine shop getting .30 over block is getting decked that fun stuff..my question is now about heads i am wanting to purchase vortec heads and i was wondering about the bolt holes for the intake are they the same as any other 87 and up intake or should i pay the extra for a 96-99 gen II small block

slowmaro87

one more thing would any carbed small block dizzy work ? considering this is a gen 2 engine...isnt there something different with how the right bank gets oil ?

HCR13

iTrader: (5)

I'm currently doing what you were thinking. I have a 305 tpi and swapping all the tpi stuff to the LO5 350. I'm using the crappy LO5 heads (because they are already rebuilt) but have a LT1 cam. I plan to just bump up the fuel pressure...

slowmaro87

i wish you the best of luck with the tpi ...i just dont want to deal with the computer crap lol

HCR13

iTrader: (5)

yeah, eventually I'm going forced induction, thats why I'd rather not deal with a carb...

slowmaro87

any help on these questions would be very very much appreciated guys...thanks

HCR13

iTrader: (5)

as far as I know, it should work. The gen1 and gen2 blocks are the same besides the rear main and cam retain plate...

slowmaro87

ok so say i go with vortec heads for this build are there any inexpensive roller tip or regular roller rockers that would work for the vortecs ?....ive seen mixed answers to this in other threads

five7kid

iTrader: (14)

'96-'99 Vortec is not Gen II.

slowmaro87

ok ...so what years would i be looking at for vortec heads? lol i am somewhat new to this..would you know about roller rockers for vortecs?...thanks for any help possible

five7kid

iTrader: (14)

'96-'99 light trucks.

Rockers are the same as earlier SBC, just need to be self-aligning.

slowmaro87

and any three castings should be sufficient ? or is there one that i should look for specifically ...thank you for response! by the way ive been reading about some of your builds ....yaa ur pretty much my new hero lol ...id love to do an ls swap you make it sound easy

the 57 is my dads dream car

slowmaro87

also with the heads coming off of a 96-99 would i have to have a 96-99 intake are the center 4 holes in the intake the same from 87-95?

five7kid

iTrader: (14)

You need a Vortec-specific intake for '96-'99 Vortec heads, whether you stay with TPI or convert to carb. The bolts and ports are completely different. Some people try to sell you on drilling the Vortec heads so a "regular" intake fits, but that's a lose-lose situation.

By the way, "Gen II" is the LTx family of engines. Only used in passenger cars (Vettes, F- and B-bodies). Optispark, unique intake manifolds, reverse flow cooling, etc.

slowmaro87

do you off the top of your head know were i can find some information on chevy small blocks through the generations it sounds like it be some good reading...thanks again for all your help can say that enough

five7kid

iTrader: (14)

First hit Googling "chevy small block" http://en.wikipedia.org/wiki/Chevrol...l-block_engine

slowmaro87

hey guys i had a couple quick questions ...this thread is becoming my build thread lol but the question i have ive been looking through pages of the seach bar and cant seem to find what im looking for ....i just purchased a a/c delete box and was wondering if anyone has installed one before and am i going to have any issues getting my heat to still work ? other couple questions i have are about the serpentine belt system my car has im not goin to have my air pump or a/c installed on my car and ide rather not install a delete pulley ide like as little belt routing under my hood as possible ...is this too far fetched? one more thing since im removing my ecm due to changing over to carb and my car is a pass-key car and my passkey module and columb dont match is there any way i could set it up to just rip out the passkey module?

slowmaro87

bump

HCR13

iTrader: (5)

if you have the correct A/C delete box, you should be able to hook it up pretty easily. Many people have done this. If it still has the blower motor, your heat should still work. As for the serpentine system, you're gonna have to put an idler/delete pulley. There is really no way around that. Something you might want to look into is swapping to v-belts. I have v-belts now and all I'm running (besides the waterpump) is the alternator and ps pump. Thats it. Just 2 small belts. Looks pretty clean... As far as the passkey, I've never dealt with it so I'm not sure, but as long as your key engages the starter, you should be fine. I think the passkey system works by disabling the fuel pump or injectors. One of the 2...

slowmaro87

thank you very much for response ill be doing the a/c delete this weekend hopefully and i may have pulleys to switch to v-belts.thats all i gotta run is power steering and alt anyway(besides water pump) im still pretty puzzled about the pass-key

slowmaro87

bump

slowmaro87

just a thought with the passkey issues the story is i took out the steering column in my 1989 iroc and replaced it with the one from my 1989 trans am then junked the trans am car wouldn't kick due to resistance on key being different than what the pass key system on the iroc was BUT i do have both sets of keys how do i measure the resistance on the iroc key chip so i can buy an uncut key with that resistance and have it cut to the trans am key??



dont know why it took me a year to think of this lol