[Rocky 389]

In trying to settle on a good engine for my 34 ford coupe project, I've been able to buy an old 347 Pontiac engine that had been left at the local machinists shop many years ago. It was bought by a buddy and was stored for many years until he decided he was never gonna get to it and I got it for a song.
The block has been bored .125 thousanths and had new [at the time] Jahns cast pistons with a pretty good lump on the domes....was assembled with stock cam and a standard crank in great condition.
I measured the deck and found the pistons were 0.040 down the bore at TDC.
I'd love to assemble this engine with late [post 64] heads because they offer screw-in studs, big valves and if I use large open chamber heads I was hoping to get the compression down to a manageable level for street use. I've been scouring this forum and doing searches to find info on this kind of build plan with limited results...some guys hate the Jahns pistons because it's said [by some] the combination of early lumpy pistons and open chamber heads will get the compression down ok but leaves a terrible quench area not condusive to good flame travel...HMmmmmmmmm I'd hate to build this 347 [now a 364] to find it runs even slower than a stock 347 with flat-tops.
I've already bought a shiny new dual quad [P_65 Edelbrock with new 600 edelbrock carbs] setup for late heads and would really like to use later heads, timing cover/11 bolt water pump
etc etc....
I'll be using a T-5 with a Winters Champ-style quick change so gear ratio problems will be non-existant.
What do ya think? Am I on the wrong track here? Man, I'd really love to use this Pontiac motor...oh, and I already have a 58-60 [actually a 57 GMC pickup] stick bellhousing/flywheel and 11 inch clutch for it.