Once again good advice is needed with a couple of engines..

A friend of mine asked me to ask you guys for help concerning his car.. It is a Pontiac firebird 1982 BUT it has a Chrysler 318 engine and it allso has a 6/71 supercharger on top. The problem that we are having with the the car concerns the carbs.. The A/F ratio is good when the car is idling maybe a little bit on the rich side and when you get it to take some revs so that it starts to get fuel through the main jets, the mixture is allso good, but the transition from the idle circuit to the main circuit is a pain in the ***. We have adjusted the accelerator pumps to give all that they can and we have allso tried to adjust the idle circuit very rich, but nothing seems to help, we have allso checked for vacuum leaks and there are none. The engine has two 750cfm Carter AFB carbs, the main jets are 3,5 millimeter drill size. The engine itself is a 1971 318cid engine form a Plymouth GTX (Argentina model). Can you help us with this issue?

The other engine that needs advice is going to be built during this winter and it is the engine from another friends 1965 Plymouth Valiant, the engine is a 360 that is going to be stroked to 408, we have a stroker kit form SCAT with cast crank, I-profile rods, forged pistons and all the bearings and stuff, but what we do not yet have is a camshaft, were thinking of using iron heads for now that flow about the same as edelbrocks out of the box, we havent decided on the intake and cam, and were allso having some difficulties finding headers for this particular body. The engine is going to be used on street mainly, but it will see some track time allso. Were hoping to get good torque out of the engine on a wide rpm range and maybe horsepower somewhere in the 450 range. Any advice concerninng such a build will be very helpfull, what kind of parts combo would get us there?