Here is a picture of my 263 project engine I have been working on for a few years. These are my home made intake and exhaust manifolds.
Std 4 barrel intake mount and turbo charged exhaust. Just ordered a set of J&E forged pistons to go inside.
I’m going to use 700R4 transmission with Bernstden adapter. The manifold logs are 2x4 square tube. 1/4 thick for the exhaust and 3/16” thick for the intake.
If I can't get my Dynaflow to stop leaking...(or a least minimize), I may do the tranny switch. Installed a torque ball kit including the shaft spline gasket....still piddles.