So he has the split box with the angled floor under the butterflies? Vacuum to the compressor inlet out the front, compressor discharge in the back under the secondary butterflies & into the intake?
That part was ok on a smallblock. It was very close to the secondary butterflies on a spread bore carb at WOT, so it was a bit restrictive.
Add a 1" spacer under the carb, and make sure you have a big carb. An 800 cfm TQ or a QJet from a big block.
You can probably get to 460+ hp with that wafer adapter. they were only about 2 inches high. Adding a spacer will help, along with a big carb. The good news is that one kept the stock linkage & cables.
We used a boxy manifold with a 3" nipple to couple the carb right to the end of the compressor inlet with a hose. That flows better, but means using a new throttle cable & kickdown cable.
That exhaust manifold was an off the shelf piece, we all used that part. The crossover under the pan can be wrapped for a little gain, but they burn out quicker when you do that. The shop motorhome had one made from stainless schedule 40 pipe & wrapped. I never had big enough balls to put a thermocouple under the wrap.
Do not run ported spark with that setup. You need to run manifold to the vac on the distributor. We usually set timing with the line disconnected at factory (smogger) numbers. Gave it plenty of advance at idle & dumped it all before boost came in.
What is the 440 in now?
B.
