I have my 392 ordered, how much power will it make?

Is this a towing application? Quick street car? C-body cruiser? Irrigation pump? You never said specifically...

But regardless of whether it's low rpm pulling power or high rpm racing power, it doesn't matter - both need to breathe. Stock '66 manifolds with 2" pipes and a tiny carb will choke it.

My advice:

- 700 to 750 cfm carb, dp for manual trans, vac sec for auto

- 1 3/4" primary headers, either tri-y or 4 tube

- minimum 2 1/2" (but 3" recommended) exhaust with crossover or x pipe

- cam choice seems on the very mild side, not saying anything on this till I know what the hell the engine is going into