Hey I have an 89 formula with a 350 tpi I'm looking to put an aftermarket throttle body on it, I haven't done much in the way of performance yet so I doubt I need the 58mm. Also what kind of performance increase could I be looking at and also does price make a difference? Thanks

 

Don't do it. .....the stock 48mm TB can handle some fairly decently modded 350's. ....and if ya go too big, you can potentially lose a little low end torque and throttle response. Lot's of heavily modded heads and cam 350s puttin' down serious numbers, and a lot of 'em still are only using the 52mm.

I would NOT get a TB first. Save your money. ....look into exhaust/headers first, then maybe a torque converter or rear gear swap. Those are gonna be the best bang for buck mods.