Hi there I recently am rebuilding a 92' suburan 350 TBI block and heads for my 88 firebird 5.0 . I am having my friends shop rebuild the engine for me. We have brang it down to nothing and Iam building it up. We are putting just a little R.V cam in it to gain some power but keep it smog legal. We have port polished the heads and bored them .60 over. Also put bigger intake and exhaust valves. I have the Edelbrock performer intake manifold on top also port polished. And on top I just have the stock Throttle body (450CFM I believe?) On my exhaust I just have some jeg shorty headers, 2 hi-flo cats and 1 flow master 44 series. Now I'm not quite sure how many horses I'm going to be pushing but I figure some were around 340. I am jus wondering if my stock 700R4 is going to be able to handle all this new force? And if any one knows if a 350ecm and 305 ECM are the same? Because jus wanting to know if I could put a 350 hypertech chip on my 305 ECM . Thank you all for help will fill you guys in on how it goes!

 

It'll never run well. First, even with all that work, those swirl-port heads still don't flow, and you'll never have good top-end with them. Second, polishing the intake ports and intake manifold is a major huge mistake, because now you'll have fuel puddling.
The trans is the least of your concerns.

 

your stock 700R4in good shape, is fine. just do the kick down install right.
youll be fine.

 

No my intake is going to be fine the mechanic told me the same but he kept it rough enough for the fuel to stick. And why do you say it won't run well?

 

That '92 Suburban 350 donor was built with the swirl-port heads. I played with these when I had unlimited use of a then-new SuperFlow 1020 flow bench with every option, and no matter what I tried, those heads do not respond to any porting. I found 5 cfm. That's it. You're better off with 624s than those 193s. Even 882s are better. Throw your 193s in the trash, along with your intake, and redo the top half of your engine the right way.

 

if your doing a RV Cam. (rpm 1800 to 4200) then the intake it Fine also.
has that intake was made for it..

most of the time guys on hear are talking about 7000 rpm and at the same time saying you need heads that flow 280cfm to Run..lol

if your doing a combo, just get the combo of right parts to do what you want it to do. you say RV Cam.. pick out heads to go wth your cam and your intake. by doing it this way you can keep most your stock parts to work fantastic with ea other gears/TQ Convrtr/ exst/ tires, will the car be fun to drive..yes..will it be fast.. faster then some.. but not has fast has others.

remember have fun.
<<< 10 sec street car fun!

 

Yes just a rv cam to keep it smog legal. And I found out today that The heads they are using are off a 89 305 tbi bored to a 355 with bigger exhaust and intake valves with port polished. Are these heads better than the 92 350?

 

About the same. they're OK up to around 5000 rpm then you choke out your motor. trust me Atilla has done lots of work here his sticky of best builds is an excellant read, great guidance, and won't steer you wrong.

 

telling anybody to toss a RV intake in the trash, when they want to use a RV Cam with it... and not spend a lot of cash...come on.. on a side note..a RV cam is good to about 5000. so if you want to save a Buck.. well now you know

 

Well that's great to kno because I am running automatic and I never rev past 5k