truckguy

looking to rebuild the motor. as of now its a stock 350 tpi 5.7l. The plan im starting off with was to bring the block to a machine shop get it tanked, upgrade camshaft with a tiny bit more lift, get some small headers, and throttle body. and tune.

im thinking about getting a bbk 52mm throttle body for the throttle body upgrade, but im reading some random forum convos saying that this aftermarket tb is problematic? i cant find any more posts, reviews, or videos online, so i need to get some advice. Mainly I want a bigger throttle body to supplement the camshaft and headers upgrades. (not looking to make big gains just a rebuild motor with a little extra)


im wondering will it cause any issues regarding being able to easily bolt it on and go and if so, is it going to supplement the camshaft well?

SUPER CHEVY66

iTrader: (1)

why not just use the factory tb? i dont see you needing a aftermarket tb for a mild build.

truckguy

no problem with leaving the factory i just thought by adding a camshaft my engine is going to request more air and a little bigger tb would be a good supplement?

are you saying an aftermarket tb might be meant for 300-400hp builds and is not really going to make a difference?

thtanner

iTrader: (1)

Unless you're doing port work on the TPI system itself, or replacing it with an aftermarket TPI setup, you do not need to swap the TB. Even then, it has been shown the stock TB can handle a fair amount of HP (400hp+).

truckguy

awesome. well thats actually good news cause i can now knock off $400 bucks off the budget. thanks for the info, ill prob just give it a clean.

86CamaroDan

I would invest in a set of runners over the throttle body. i heard somewhere their good for like 1000 cfm - wether that's true or not i don't know. I never saw any pressure drop on my data logs when i was NA

truckguy

are runners the tubes that connect the top of the intake manifold to the head?

86CamaroDan

The runners are the biggest horsepower limiting factor of the TPI.
http://fcrcmachine.com/i-20154510-ed...d-runners.html
The gains from a bigger throttle may not even have any effect because the runners are still the bottle neck of the intake.

truckguy

okay so i can put these in and tune for more air to work perfectly with the cam?
if i bolt on the runnners will it just automatically start sucking in more air?

86CamaroDan

I would suggest you port the lower and upper manifold to help it flow nice. I would assume seeing your moving more air that you will need to make some minor adjustments to your tune

truckguy

also i thought the heads were the biggest limiting factor the the tpi. i read it in a hot rod mag article on building a tpi 350

truckguy

how much should i port the intake?

86CamaroDan

To match the runners if possible