OK guys im going to get an 87 350tpi long block this weekend. it was pulled 2 yrs ago at about 95k and Im going to rebuild it for my 91 rs to use with tbi. Im going to use the same heads prob with a little porting and thats about it.

question # 1 is will by modified stock tbi with #55( or #65 ) injectors and edelbrock tbi intake be enough to support this motor. or should i go with the holly 670 and intake..
I have stock fuel pump right now.

questioin # 2 is cam choice my choses are the stock 350 tbi cam or aftermarket something .. open to sugestions as long as its not that hard to tune.

the rest of my mods are below, im hoping for low 14's with this combo

thanks
:rockon:

 

let mw state that my cam choices are a 350tpi not 350 tbi stock cam or something aftermarket

 

Phew I was going to say....
Anyways, you will be happy with that L98 cam or an LT1 cam. Both are easy to tune and provide a nice boost in power. Since you are porting the heads I would go a bit bigger on the cam. I would look at an LT4 cam. Bigger than the previous two I mentioned but tunable and within the limitations of the L98 heads. You can go bigger if you have the heads machined to do that. You are going to have a tough time feeding that thing with the stock TBI unit. You have the right idea about injector upgrades but I would recomend a new fuel pump and a larger TBI. You are also going to need to tune this new motor and that will require chip burning.

 

i know chip tunning is a big part of it so im expecting that.
would the stock fuel pump be able to handle a holly 670 with say #55( or 65) injectors?

 

No. Maybe at idle but it will never maintain the psi you will need at WOT.

 

ok well ive been looking at fuel pumps anyway and i found that thuderracing sells this pump below and was thinking of getting it and i have a jet tbi regulator that i have in my garage already


61-12-903 Holley Performance In-Tank Fuel Pump, 255 LPH, 1985-1992 F-body 5.0L/5.7L
$154.95


so assumign i go with that. woudl it matter what injectors i get # 55 or # 65??

 

shifty: why wont the stock FP flow enough for a 350 cid? is it that weak? i would think the 65 lbs may work but will be marginal if the cam is swapped to more aggressive. i would think 80-90 lbs would get you safety margin at WOT. tuning? of course.

 

The stock fuel pump is very weak and it will probably hold psi up to say 15 at idle but once the engine is put under load and needs a consistent 15 psi through all RPM, the stock pump will fail and drop the pressure.

 

Bron is right. A high flow pump is needed to maintain 15+ PSI at full engine load at high rpm's. The stock pump can barely feed the stock motor no less one that is making twice the power than the stock one it was meant to feed.