305 To 350 Swap

[thefuzz]

ok guys I'm going to swap a worn out 305 that SOMEONE previously put in my 1990 chevy 4x4 truck with a 5.7L with 52K miles, that I drove for 2 weeks, out of a G20 van.

My question is: I want to replace the stock heads with a set of good heads, replace the cam, lifters,timing chain & gears, oil pump & screen,water pump,headers,complet exhaust..!! NOW !! should I keep it TBI or put a CARB. on it ?? wich will give me the best performance? and fuel milage? and least problems ??

 

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[beave84]

Thats a tough one, with all the up grades I think your gonna need a tune on the PCM in order to get the most out of your combination. Have you thought about just selling the 350 and dropping in a crate motor. Everything your gonna do to the 350 you could by a complete 383 Blueprint engine with plugs carb distributer water pump etc from Jegs that makes 330 horse and has a 3yr/50k mile warranty.

[GMstrong]

edit:"Alot of people swap TBI to carb because their "cams" are very agressive sorry i messed up below..Theres no hp gain swapping to carb.Alot of people just swap tbi to carb because their is very aggressive and requires a custom chip which people dont want to wait for and spend 375 dollars for.The TBI system is a pretty damn good setup its just the parts around it such as the heads,intake,cam are what make it what it is.keep the tbi350 put eforce heads on it,port and polish intake mani and TB,adj FPR,vortec fuel pump or equivalent,nice melling cam and lifter kit,some better valve springs,self aligning rocker arms will allow for a bigger cam too.This setup will make you smile.but you'll really be happy with a built trans,4:11 gears,2800 stall.

[thefuzz]

edit:"Alot of people swap TBI to carb because their "cams" are very agressive sorry i messed up below..Theres no hp gain swapping to carb.Alot of people just swap tbi to carb because their is very aggressive and requires a custom chip which people dont want to wait for and spend 375 dollars for.The TBI system is a pretty damn good setup its just the parts around it such as the heads,intake,cam are what make it what it is.keep the tbi350 put eforce heads on it,port and polish intake mani and TB,adj FPR,vortec fuel pump or equivalent,nice melling cam and lifter kit,some better valve springs,self aligning rocker arms will allow for a bigger cam too.This setup will make you smile.but you'll really be happy with a built trans,4:11 gears,2800 stall.

 

 

GMstroung with THAT combo OR my set up using the Tbi your saying I WILL have to buy a $375. computor chip correct ??

[GMstrong]

My fault Brian at TBIchips.com says 275 or so shipped.Yes as a matter of fact youll need the whole ecm from the 350.Grab the ECM from the 350 or get one off of ebay.And if you go the route i said in my post then you will need a custom PROM.You can do it yourself for 50 if you have ALOT of time and a good laptop.

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I'd swap to carb, IMO, you're wasting you're time switching heads/cam and still leaving that restrictive tbi on there. And also, there's not a lot of great options for tuning a tbi, it's nothing like efi systems of today. Tbi's are great for low end torque but not much more. Everything(heads, cam, manifolds, tbi) sucked on those engines and you're wasting time and money not replacing all of those restrictive parts.

[GMstrong]

you can get the TBI system to flow 640cfm.yes it restrictive if you leave it stock.a carb swap wont help the heads,cam and intake.go to tbichips.com give him an email telling him what you want.but ill admit ive been thinking about swapping for an LT1.If you feel like swapping then yes that would be better for you but not too many people have a nice shop or garage to work in or a woist and the man muscle to pull it out.

[ta2whitey]

I am considering doing the swap for my 85. I have never done it with a Chevy. ECU is obviously a big concearn and depends on what year engine. The transmission should match right up though?