if i'm going to swap from a tbi 305 to a 350 tpi running around 350-400 hp what do i need to upgrade on my drivetrain and suspension to accomodate the extra power without breaking parts?

 

get the tranny rebuilt and put in a ~2400 rpm converter. go ahead and put in a posi unit and some 3.42 or 3.73 gears with a solid pinion spacer(this solid pinion spacer keeps the front of the case from flexing and will keep the pinion gear from trying to climb the ring gear, which is what causes the most common failures in the 10 bolt rearend). poly bushings in the stock suspension components will suffice but if you want to replace stuff with aftermaket tubular stuff, either www.spohn.net or BMR Fabrication Inc. for that stuff. also, get you a nice set of weld-in subframe connectors...though i'd do this before ANYTHING else...to include your 400hp tpi motor.

don't forget that you need to upgrade your fuel pump cause the tpi requires 40-60psi (depending on combo) and the tbi pump only gives you about 18psi max.

 

thanks for the info
what about a torque arm? and i didn't know about the fuel pump, i would not have known to do that!

 

an aftermarket torque arm is not necessary at that power level. i would suggest putting a poly mount for it up front as well as a poly tranny mount. also, i'm a firm believer in lca relocation brackets. go check out the suspenion/chassis board for the sticky on how they work and why they are necessary.

my old 350 went a 1.649 60' time on micky thompson et street radials, stock lca's that i boxed, spohn lca relocation brackets, spohn panhard rod, stock torque arm with poly bushing and poly tranny mount. i put a set of jegster bolt in subframe connectors in it, but then i welded them in and put some extra bracing in cause they weren't sufficient. the new 305 has already been 1.694 to the 60' with the same suspension combo and i haven't gotten it completely tuned yet.

 

A 350 horse TPI is a very ambitious project. And very expensive. Basically none of the factory TPI hardware is going to remain when you get done (except the plenum, which you will have to port, and fuel rails, maybe). All aftermarket TPI equipment is expensive: Base, $400; runners, $350; throttle body, $260-$500; injectors, $250. Plus gaskets to put it all together, of course. Or, maybe just go with a full system like the Super-Ram, $800. It doesn't have any guts below 3000 RPMs, so you're going to need at least a 3000 RPM stall converter. And doesn't include injectors. Or throttle body.

I hope you realize I'm not trying to discourage you, just inject a dose of reality.

Oh, didn't see mention of subframe connectors. Vital 1st step, IMO.

 

With LTRs 400+ ft/lbs is EASY, 400+ HP is impossible without serious breathing modifications.

 

 

Okay, I'm blind in one eye and can't see in the other. . .