Mines a late model roller and I love it. Still looks old school but has nice pretty rollers under those old rocker covers and that Motorsport intake. You cant see any difference externally so why stay flat tappet? Roller motors are affordable and easy to find. More power and economy.
If your truly wanting to keep it a all stock 302, the 1968 302 4V from the Mustang and the Cougar had different heads on the 4V engines and this would be the very best factory 302 in my opinion. The combustion chambers are much smaller at 55cc (I think) similiar to the older 289 heads and give a true 10:1 compression ratio. This is the head that all of the 302 NHRA Super Stock racers use when using the older 302 in class racing. The part number is C8OE along with a a 302 4V cast into he underside beneath the intake ports, towards the deck side of the head.
Even if you swap to small chamber heads it wont help, up until 77 I think 302 had HUGE dished pistons, Swapping to (53cc)289 heads only gained me .6 in compression So it went from 8.1 to 8.7. Not even worth it.... EDIT: you could swap to Flat tops though....
My first personal choice would be to use a late model roller engine with flat top pistons and a set of GT-40 heads milled. The GT-40 stuff can be found anywhere cheaply; they even came on the later V-8 Exploder's. In a nut shell, it all depends on his budget and how much he wants to get involved as far as his engine project
The best 302? Well....2011 is by FAR the best factory 302 IMO. Push rod wise....the 69/70 Boss 302. Period!
He's right And you can make a scaled down BOSS 302 by adapting 4 BBL Cleveland heads to a regular 302. Not really worth it today with all the cheap aluminum heads out there for Windsors though. One thing: All factory 302 and 351 Windsor heads are a joke flow wise. Even the GT 40s are restrictive by aftermarket standards. And the 2011 BOSS 302???? Ford's lying. 444 HP? Not really. It makes around 470 at the crank