Hey fellas, i know this forum is for 3rd gen cars and theres countless amounts of threads on this issue and what not but this thread id like to explore what you guys think some good mods to do on a tbi 350 in a truck would be. I got a 94 chevy silverado. Id like to know what are a few things i could do on the motor to get some more power. Maybe an intake, headers, possibly some head work, maybe a cam. If a throttle body spacer is worth it. I know those stock tbi heads are a big choke point so any ideas on what i could do with them are possibly put 350 vortec heads on it? Ive never really messed with an older 350 like this one so im just looking for some ideas. Thanks for any input fellas.

 

Put some headers and full exhaust on it. If you don't have emissions testing you can put some vortec heads on it, buy a different intake manifold for vortec heads with a tbi adapter. Buy Rbob's EBL flash www.dynamicefi.com to do the tuning duties because you'd have to burn EGR out. A cam would give some more power to you. But remember you gotta get it tuned. So whether you go with the link or get a custom chip burned. I'd change the air cleaner also. Put some sort of cold air kit on it or if you have a cowl hood some open element cleaner.

 

Thanks for the info man. We dont have emissions testing up here in northern wi which is nice. ill have to look around for some nice vortec heads. The stock tb should be good enough right?

 

it would be fine. do the ultimate tbi mods, upgrade the injectors. you gotta think about how much HP you want. and build according to that.

 

Im thinkin id like to get around the 300 hp mark. Id be happy with that

 

Im thinkin this for a cam
http://www.compcams.com/Company/CC/c...?csid=198&sb=2
With this intake
http://m.summitracing.com/parts/edl-...Fck7MgodoycApQ
These headers
http://pacesetterexhaust.com/88-99-g...ukon-BLEM.aspx
And of course vortec heads

 

I installed Edelbrock TES (Tubular Exhaust System), a high-flow aftermarket cat, and the Flowmaster 3" cat-back exhaust on my '88 K1500 when I replaced the original 5.7L engine with the '92 Caprice long-block "crate engine" p/n 12513151. (adds (very mild) roller cam and higher compression flat-top pistons (9.6:1) compared to the original 9.2:1, retains the shitty swirl-port heads.)

Power improvement was real, but marginal, even though the original engine had 235,000 miles. Fuel economy also improved--but again, only slightly.

The stock cams are not just weak, they're helpless.

The stock swirl-port heads are unmitigated garbage.

I have heard, but cannot confirm, that the OEM intake manifold is horrible in terms of mixture distribution. (anyone else confirm or deny???)

My plan--which I have been collecting parts for but have not yet begun wrenching on, is to install aluminum aftermarket heads, retain the stock cam but with 1.6 rockers, a GM Performance Products "ZZ" crate-engine intake manifold (same thing as an Edelbrock Performer EGR, but half the price on the used market--typically about $100 shipped on eBay), a 7.4L Q-jet-to-TBI adapter. Retains EGR although I think the actual EGR valve will have to be different due to bolt-pattern differences. Biggest problem will be to lengthen the fuel plumbing as the throttle body will be considerably higher than stock.

Earlier plan was to use Vortec-style aftermarket heads which are factory drilled for the older, non-Vortec intake manifold pattern. I still have the heads (new castings, still in the boxes--never had valves in them, and currently for sale) but they didn't have an exhaust crossover provision, so EGR would have to be supplied by a crossover pipe direct from the exhaust manifolds/headers.

Most parts bought and stored, I can't bring myself to open the engine because the truck runs perfectly. Driveability is simply wonderful except for not having a lot of power.

The trucks already have cold-air ducting, to the right fender area. No change needed provided there is adequate hood clearance with the new intake manifold/TBI spacer.

 

Yeah i dont have to deal with emissions testing up here so thats kind of nice. Im even considering some aluminum heads depending on what i can find