[tomcat racing]

youve spent the money on the engine, so do it justice and have a custom set built, ive got similer engines in my xy ute and my cobra same heads etc, for that combo 1 3/4 inch primaries at the port then stepped up to 1 7/8 inch, 32 to 34 inches long 4 into 1,to build maximum torque, anything less is a compromise. i also notice youre using a super victor intake, you are also going to lose low end torque with that manifold so i wouldnt suggest block huggers or shorties if you dont want a double whammy, a victor junior manifold or even a performer would probably work better on a 347 for street use, but i dont know youre engine specs or what its intended use is. cheers