power potential of vortec

[66shortwide]

guys,
what is the thought on how much power the stock intake/injectors can make off of the vortec(1998) 350? Was thinking of a 383 with aluminum heads and a decent cam(nuthin crazy), but I'm concerned that the intake/throttle body/injectors won't be up to the task. Any comments or ideas would be appreciated.

[sleric77]

Hey I'm having the same problem with a truck that a friend of mine is working on. We have a 1996 silverado with a 383 stroker motor. We're still running the fuel injection but it does't seem to be getting enough gas. The idle is also very high and you can even hear the cam at all. we had the computer programmed twice but we cant find the problem. The stock engine runs better than the stroker engine with aluminum heads.Any info you get could help me a lot and if I get any I'll get back with you.

[66truckin]

It will be a night and day difference when you swap those vortec heads on. Escpecially if you go with a little more aggressive cam.

[metalgod]

did you sinc the crank and cam wrong? what fuel pressure do you have at the fuel rail at idle and what do you have under load.


......i have a 96 tahoe 2-door with a 300whp 355 and i went through some problems getting it to run so i can help you if you need pointers

[metalgod]

Originally Posted by sleric77

Hey I'm having the same problem with a truck that a friend of mine is working on. We have a 1996 silverado with a 383 stroker motor. We're still running the fuel injection but it does't seem to be getting enough gas. The idle is also very high and you can even hear the cam at all. we had the computer programmed twice but we cant find the problem. The stock engine runs better than the stroker engine with aluminum heads.Any info you get could help me a lot and if I get any I'll get back with you.

computer reprogramed?..........what did they program? and whats the warm idle at ?

[sleric77]

I'm not at the shop until friday so I'll get you the info as soon as I can get back down there about the programming.

[junkman8302]

Everything I have ever heard is that 400 is the absolute max you can squeeze out of the stock Vortec truck intake and injectors. Although there is the marine intake setup that has been discussed several times here and on other boards. There is also a crate engine that GM offers that is a 383 with aluminum heads and a hotter cam (LT4 cam i believe) that will work with the stock computer program and intake. GM claims 340 hp and 440 ft-lbs right out of the box. I have found the engine on their website, they call it the 383HT. I'm sure that the cam specs are advertised some where and the engine could be built at home without laying down the precious coin on the entire motor.