The thing that I keep wondering about when talking if the 454 TBI will flow enough fuel is what are the respective RPM limits of each engine. I know that while they can be rev'd higher than they should be (think bowling ball sized main bearings), that the whole point of the 500 is to not have to rev the snot out of it. If that is the case perhaps the 454's flow isn't too far off?
You might have read something I wrote. The 460 intake's runner spacing & port shape is a nearly identical match to the Cad 472/500 engine. The bolt pattern is nowhere close. Typically what happens is that you modify the flanges of the intake to have the Cad bolt pattern.
The other issue is that the end rails are also totally different. That requires making some filler plates of the right shape & welding them to the intake.
The boys in the Edelbrock both at SEMA were upset when I asked if they just modified an old 460 masterplate to make their 472/500 intake.
As to the dizzy part, I've put the upper part of a Chevy HEI in a Chevy Points body (both a cast iron one and several aluminum) and the upper of a Chevy HEI in a Buick points dizzy body. I have no doubt that the upper of a TBI dizzy could be adapted to a Cad HEI or Point dizzy body.
I've not done it though so I'm not sure what the exact steps might be. If anyone has both dizzys & is willing to ship them to me I'll look into it and see what's required. Doing this sort of conversion is a side hobby of mine. So far I've put Ford D-S II stuff in I-H dizzys, Yota & Subaru stuff in ACVW dizzys, Yota stuff in flathead flat fender dizzys, and various GM HEI/points conversions. The D-S II > I-H is the most involved as I have to fire up the surface grinder & Spindex to grind the points cam down to the reluctor's ID.
PM if interested.