c/k TBI truck power?

I know someone who is looking to get more power from a 350TBI in his chevy pick-up. He's asked me, and I told him the best way would be to perhaps swap to something that's more inline with what he'd like...which he's considering....since he's planning a rebuild of the engine at a minimum (230,000++ miles)

I really don't know what the realistic expectations for a TBI engine...I know many disdain them, but it does appear some do upgrades, from computers (chips?), to cams, headers, rockers, etc....

So he wants to weigh his options and kind of go from there. What can be done for the TBI

Well I know chips get burned for them at Wbd all the time. Just like anything else, heads, Cam, intake and headers with a tune is prob worth 100 to the wheels.... Also could go larger ci too but keep in mind that 2barrel intake will always be in the way.

Dished pistons + swirl port heads (IIRC) are two of the big issues I always understood. Of course the injection setup is also an issue. My LS's 350 was from a 87' TBI mini School bus...yep, best donor vehicle ever. I can't see bothering to do a chip to an otherwise stock TBI motor but admittingly never looked into it.

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Originally Posted by PB86MCSS

I can't see bothering to do a chip to an otherwise stock TBI motor but admittingly never looked into it.

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Well, he's looking to rebuild the engine and hopefully get up around 300hp or so...

At first, I wasn't sure that the TBI system would allow this, but it looks like it's seems feasible reading around.

Basically it seems to suggest that the key is keeping vacuum up around 17 or so inches of mercury. Offsetting any bump up in cam duration with a bit of compression.

He might be happiest with a basic rebuild w/ 9.5:1 compression (or something in that ball-park), 204-208 @.050 duration cam (which even if carbed, would work fine w/ 2bbl), and headers...it does seem to suggest that a new chip would be warranted. Should make a lot more than the 210hp it made stock...and perhaps a little better mileage.

Although, I think he should take my advice and just buy a nice low mileage vortec 8.1 or even an earlier LS based 6.0.

Depends on how much the truck means to him, what shape it's in I'd say. If clean and he plans to keep it quite some time, an LSx swap would be nice. Of course budget is a big role, with LS swaps getting more and more common they are surely more reasonable, I haven't priced it out myself. But if he is willing to do heads, cam, headers, etc....might be getting close to the same, or close enough to justify it. If I had to do an EFI swap today vs. in 02' (when I did mind) or if I wanted to make serious power in my LS, I'd probably go that route. Doing headers and a cam with a tune to match the cam should get him somewhat close to 300 I'd think.

I like the TBI 350 because it is dirt simple with good torque. The most power you can make out of them is in the ~315hp because that's all that two 100lb/hr injectors can handle. If you do a referenced fuel pressure regulator you can get more out of it.

Vortec heads, a set of headers, and a heated oxygen sensor is about as much as is worthwhile.

My dd is a '94 extended cab 2wd. It came from the factory with a 3.73 limited slip rear, and the previous owner did the bolt ons. It has a JET chip, shorty headers, cat back 3" system (no cat), injector spacer, tb spacer, adj. fuel pressure regulator, and best of all....the GM hi performance flipped over air cleaner lid, lol. I've had a couple other 350 tb trucks, and this one is way more fun to drive than the others. It's probally mostly due to the 3.73's vs the normal 3.08/3.42's....but it also pulls down 17-19 mpg, tows awesome, parts are cheap, and it's simple to work on.

What seems to be the norm is a vortec head swap and a "ultimate TBI mod" which is grinding the lips out of the throttle body and grinding the bars that hold the throttle blades. People report it helps ALOT.

Do a homaide intake tube. Get rid of the big box on the fender and run a PCV tube to the side and use the stock fender plastic piece.

Also a 90 camaro 5.7 fuel pump the stocker one you cant get more fuel out of.

Also the "quarter mod" to raise fuel pressure. Take the regulator apart and put a quarter under the spring and reasemble. You can get a couple extra LBS of fuel pressure. Its a old dirt track trick.

Ebay headers (the stainless ones that are shorties with the ballflange. Cheap and look nice and work really good. I picked up some bottom end.

A injector spacer and a TBI spacer also. If you do the vortec intake you gotta get a trans dapt spacer to go from carb to tbi.

You can usually bump up the timing also. Not much but it does help out.

The TBI heads SUCK for flow. The vortec cam is a Iron head LT1 cam out of the impala.

Cheapest way is get a vortec longblock and go that route. All the extra stuff helps but doesnt wake it up as much because the heads suck that bad.

As for tuning I havent gotten into that with the TBI. With a adjustable FPR it seems with minimal mods you can get it pretty good. but dont qoute me on that. just from Fullsize chevy .com when I was doing my mini buildup.