performance upgrades for 88-94 TBI chevy truck....?

Lots of experience with modding this engine/EFI combo. First step is headers; there are a TON of them on the market, so pick a pair of full-length (NOT shorties) headers and get a decent high-flow cat and muffler combo. ECM (computer) will not have a problem with this at all. You'll find an extra 20HP here.

Next step up would be a set of cast iron Vortec Heads ($259 each brand spankin' new) and a GMPP TBI intake manifold (another $250) to fit the new heads and TBI unit. That combo will net you 20-40HP, and might require a PROM reflash for the newer heads.

A cam would be great at the same time you did the heads, and will also require a PROM reflash.

Doc

Good deal DOC, thanks..... I've been checking out some headers online but have only run across "shorties". Any idea where to look for a set of "Full lengths"? And do they make a dual conversion kit? I heard that Flowmaster made one for the CK series pick-up but haven't seen them yet.......

I'm also considering maybe just buying a stock 5.7 crate motor and adding about a 480 lift cam (maybe not quite that big)

~John

Flowtech Afterburners... they're under $200 for non ceramic coated headers, an additional $100 for the Y pipe. you can get them from Jegs, summit, JC whitney.

not one that's legal for on road use as the TBI motors all had a single cat

I heard that Flowmaster

a true dual or a split after-cat system? if you're just looking for a split system, everyone and their brother makes one.

HTH, Bret

a true dual or a split after-cat system? ===================================== True dual.......not cat-back.

I have done a lot of research on the TBI ?COMPUTER match, I have put in a Comp Cam made for TBI , shorty headers, years ago a HyperChip, free flow exhaust. I am very happy with these mods, there have been no problems at all. I am going to the Edelbrock Aluminum heads and intake next. The rings never seated in, so a good reason to put in the new parts. I am hoping with all these mods to increase the HP from stock by about 60 to 70 HP. The tranny has a shift kit and the rear end now has a new posi.

I still have not got a yes or no from the group, on whether I will have to do a chip change again. I will keep you posted, on that subject. I am hoping that these are not to drastic of mods for the computer to keep up with. If I need more fuel, may work on the stock TBI system.

If any one has done these mods and have had to change the chip please let me know.Also do a search on this site on "TBI-computer" and you will find about 30 posting on your questions.

A throttle body spacer will greatly im prove fuel atomization. You will get more brake hp and your fuel efficiency will increase at the same time, which is a big bonus.

A throttle body spacer will greatly im prove fuel atomization. You will get more brake hp and your fuel efficiency will increase at the same time, which is a big bonus.

How do I get more hp in my 88 chevy 350.5.7 truck?

The truck is pre 96 and no longer has to go thru emissions(at least thats how it is here in WI). So you can run a true dual from the headers without cats(the way it should be) and it will perform and sound a hell of alot better

Same question only it must pass California smog I'm a southern California resident.