I just had a 350 built. It is built .030 over. It has a Lunati street cam, roller rocker arms and popup pistons among other things. It is a 375+ hp engine. I just got a brand new weiand hi-ram intake that was purchased in 98 but has never been used. It has the base that can accomadate 2 4bbl carbs and the top that fits 1 4bbl carb instead of the two. I was wondering what size carb i should put on this intake. I will be using this engine on the street and strip.

You might get a better response in Performance or in Engine and Drivetrain.

If you do the math, Engine Size (CID) X Maximum RPM / 3456 = CFM @100% Volumetric Efficiency you get the total CFM needed so devide that by the number of carbs. But you also need to know that your engine probably isn't running at 100% volumetric efficiency more along the lines of 80-85% so if you were to do the math... engine size = 350 + (350 x .03) = 360.5

360.5 x 6000RPM/3456 = 625.87 but thats at 100% so we multiply 625.87 x 85% (max) we get 532CFM need total for the engine.

Truthfully I think the intake is going to hurt the motor more than anything. I think if you went with an edelbrock performer rpm air gap intake, you would see a 10-15 hp gain up to about 5000. As far as a carb size that depends upon rpm of the motor, but for a street strip motor of about 400 hp with a 6500 redline, a 650 dp holley will work well.

Get a nice Dual plane manifold and Holley 3310 or street avenger 670. The tunnel ram is going to kill your low end torque.