I have never gone to the my cars limit, I have always backed out, but I have thoughts. I have that intake manifold in a 427 replica, and I realizeit was designed for a great big Galaxy. The engine sat with a rear down incline for
oil drain back and to get the coolant thermostat as the highest point and lots of hood clearance. Back then, 900 CFM or larger carbs were not heard of. In my replica the engine sits almost flat that puts my carbs at a front down incline and I have a pair of 600 CFM Holley carbs with a pair of trimmed down S&H air cleaners. I feel the air cleaner are restrictive and still leave marks on the underside of the hood. I would rather have a free flowing manifold (maybe a slight air gap), carb base sits flat with my engine , multiport fuel injector bosses (probably custom made)The carb base being level probably wouldn't matter with multiport fuel injection. If it could made to look old school the better. I'd put a large single throttle body and cover it up with a big air cleaner. The old sidewinder intake starts sounding better all the time. OR, how about a large air door with ram air ducting from the front air ducts on the body. At any rate the whole system would need to be planned together because working with the old always calls for compromises. I find myself trying to reuse something that I have that doesn't really work with the new. Money and labor are always a concern.
I'm preparing for retirement and everything on this car works beyond my limits. My old stuff probably has no resale value to anyone else as my heads and intake are milled to fit with each other on a standard block. Lots of work has been done to the heads and intake and It started as 11.5 to 1 compression ratio., It's probably slightly higher now. Buying the best pump gas and adding stuff has worked so far. It sits in the garage and is ready to go at a moments notice to go farther than I can afford to buy gasoline. I don't want to turn it into a virtual boat ( a hole in the water where you pour money)