I'll start with a description of my car. 66 coupe with 306 ,GT40p heads with I believe trick flow springs, 1.6 rockers, trick flow hydraulic lifters , trick flow stage 1 roller cam, edelbrock 500 cfm carb, Weiand stealth intake, flamethrower distributor, performance automatic trans with 2600 stall and 3,55 gears. Car starts fine and runs ok but its got no get up and go! Ive checked everywhere for vacuum leaks. Timing initial is 16 and 38 at 3000 rpm. Pulled plugs and other than a bit black seem ok. Tried to check compression but with these heads, its nearly impossible to do, no room! Any ideas?