There is probably a reason aftermarket companies didn't continue with the cleveland heads. With the huge valves and ports, velocity was down at low rpm. You really have to rev them to get to the power band. Modern head design factors this in and you have more useable power. I know www.powerheads.com sells cleveland heads. This brings me back to the boss 429. The engine is very powerful stock, and how it looks is great.
Hemi type heads, they make the whole engine look meaner and bigger. I wish the aftermarket made such an offering for the windsor motors.
theres a reason the boss 302 had 4 bolt mains.. a standard 302 will have a hard time surviving the RPMs needed to use a 351c head... you'd be better off using the 2v 351c head... but aftermarket alum heads actually flow better than the 351 heads.. as well as having to modify the heads and block to match the coolant passages...
there are a set of hemi heads for the 302.. cant remember the name of the company.. but they're something like 6k a set...
Go here (http://www.allfordmustangs.com/Detailed/630.shtml), input your head comparison, and knock yourself out. I think you'll find about anything you'd want to compare. The numbers may surprise you. Others have alluded to it already in the thread - newer head designs offer great flow AND reasonable low rpm velocities to keep bottom end acceptable. Any one that's ever driven a Boss 302 can tell you, they were pretty much a dog below 3000 rpm - which is why most of them were geared out the whazoo - you had to get them up above 3500 rpm before they woke up. To the original posters point - it is more possible than ever to have high rpm fun without paying such a low rpm price.
www.pricemotorsports.com and www.dscmotorsport.com will supply you with any adapter or intake you need for ANYTHING. Everyone should check them out. I've always thought it would be cool if someone did an EFI clevor because you could if you used adapters to mount a 5.0 intake on a clevor and if you wanted to go the 4V route you could use a Vic Jr. EFI intake.
my dad has a 70 boss 302 and that thing can flat out revv the only problem is the torque sucks even with a 391 gear in it my lx pulls harder out of the hole but nothing sounds better than a small block screaming to 7 k all the while blasting detroit rock city thru the factory 8 track !!!!!!!!!