Is 300 hp possible from a tbi

[westsoundred]

I have a 1992 pre-Vortec 350 that I am going to have to rebuild/replace at some point and I've been pondering an upgrade. I don't want to go to a carb (i like the reliability of the TBI). I'm contemplating a Vortec long block and possibly a Holley 670 TBI. My cat is gone; the previous owner took it out, and I have a Flowmaster 2" exhaust. I know next to nothing about performance chips, and I'm a little wary of a cam upgrade unless it comes with the long block. I don't trust myself not damaging the cam while putting it in, but I can be convinced to take a risk with enough coaching.

What is a realistic expectation on horsepower for such a build? Could I get to the 275/300 hp range with that setup? Does anyone have experience with this kind of build? I realize I'm shooting for the moon a bit here, I want reliability, fuel economy AND hp - or at least more then I have now. I'm planning on this build for next fall/winter, so I need to start saving the money and acquiring parts now.


thanks for the help/info,

 

[Redneckgeriatric]

if going with a long block, dont waste time/money/ complications with a cam change. if wanting more cam, build motor around the cam that fits your needs.

you are being unrealistic with stock long block and 300hp. set a realistic torque expectation, and reach it easily with stock longblock. and will appreciate tq much more than hp, and save tons of money you can use for keeping the old chevy up and running.
IMHO

 

[Supercharged111]

The tune will be the hard part, but TBI can support that. I'd either punch out the stock TB or get a BB unit. Vortecs were good for 255hp stock, so nothing unreasonable about adding 20hp to it. Hell you pick that up with exhaust and a tune anyway.

 

[Gramps]

My goals were similar, needed a fresh motor and wanted simplicity and driveability. Took a tbi block with roller provisions, comp roller cam, vortec stock style roller lifters and retainer. Stock type dished pistons. EQ iron hybrid heads.(vortec 64cc chamber with tbi intake manifold pattern) stock intake manifold, tbi with some of the “ultimate mods” and stock ecm/chip. Purrs like a kitten, pulls like a mule.

made 311hp/385ftlbs on the dyno.

So yes you can achieve what you are asking.

 

[L31MaxExpress]

My goals were similar, needed a fresh motor and wanted simplicity and driveability. Took a tbi block with roller provisions, comp roller cam, vortec stock style roller lifters and retainer. Stock type dished pistons. EQ iron hybrid heads.(vortec 64cc chamber with tbi intake manifold pattern) stock intake manifold, tbi with some of the “ultimate mods” and stock ecm/chip. Purrs like a kitten, pulls like a mule.

made 311hp/385ftlbs on the dyno.

So yes you can achieve what you are asking.

Stock TBI unit with 454 injectors and stock chip IIRC. Stock TBI unit can make about 330 HP at its best with normal compression and cam design. Design the engine as a 2bbl restrictor plate setup and could probably crest 400 with the stock size TBI and raised fuel pressure or larger injectors.

 

[Gramps]

Stock TBI unit with 454 injectors and stock chip IIRC.

Correct. The goal in this project was turnkey driveability and reliability.

 

[LVJJJ]

Buy a 383 stroker from S&J engines in Spokane. Got mine for $2300, remanufactured long block with roller cam, haven't dyno'ed yet but they estimate 350 horsepower. After towing with it, I think its at least that. Friend of mine installed it for $1100.

 

[westsoundred]

Buy a 383 stroker from S&J engines in Spokane. Got mine for $2300, remanufactured long block with roller cam, haven't dyno'ed yet but they estimate 350 horsepower. After towing with it, I think its at least that. Friend of mine installed it for $1100.

did your tbi bolt right on, and all accesories? and was the 350 hp witht he tbi or BB?

 

[westsoundred]

My goals were similar, needed a fresh motor and wanted simplicity and driveability. Took a tbi block with roller provisions, comp roller cam, vortec stock style roller lifters and retainer. Stock type dished pistons. EQ iron hybrid heads.(vortec 64cc chamber with tbi intake manifold pattern) stock intake manifold, tbi with some of the “ultimate mods” and stock ecm/chip. Purrs like a kitten, pulls like a mule.

made 311hp/385ftlbs on the dyno.

So yes you can achieve what you are asking.

Did you keep your shopping list?

 

[Gramps]

Did you keep your shopping list?

Of course