I currently have a stock 350 TBI with 150K miles. Time for a new or rebuilt motor. I have studied the archives but am unclear as to the best way to go. My requirements are that I need about 400 ft/lbs torque and 300 - 350 HP (net flywheel.) I would keep the TBI but my calcs show that I would need 100lb injectors which are unavailable.

Is a stock TPI manifold on a built long block an option here, or would I need to look at an aftermarket intake?

 

Do you want 400 ft-lbs at the wheels or crank?
At the wheels you really need to get an aftermarket manifold.
At the crank it can be done fairly easily but the biggest HP restrictions are the factory exhaust and intake manifolds.

 

http://www.chevytalk.org/threads/sho...true#Post74975

 

crank, my stock 350 TBI has 300 ft/lbs torque I need 400. With the right cam/heads can this be done with a stocke TPI intake?

 

ok first.. get ride of that TBI ****.. if u can afford a new engine.. u can afford a new intake. granted.. u can make 400 tq but the TBI is RELLY killing ur performance.

 

that is what I am planning but I need to know what the limits of the stock TPI mainfold are, can you build a torquey engine with the stock TPI intake?

 

Did you read the chevytalk post?

 

if u dont have a tpi intake now.. heck.. even if u did.. y keep it stock? atleast port that stuff. u will ahev to anyway. i jept TPI as my intake.. but ther is NO way a 406 could breath with a stock tpi. but u just have to port it.. and ur good. and i mean PORT like make the whoels go from this big O to O

 

A bonestock TPI puts out 330-345 ft-lbs already so yes 400 isn't too far off. With a hotter cam and heads and the stock TPI you will achieve your goal but at the same time you will be seriously restricting the engine's power potential.
To answer your question: Yes a built longblock can make 400 ft-lbs with the stock TPI.

 

Torque is good......