I am modifying a vr v6 i already got the block bored 20thou and 20thou pistons, conrods balanced and crankshaft balanced that using standard engine bearings. the camshaft been modified and balance to be used without balance shaft. Is it with while using these parts i am listing for the heads 7333-12 6 (6 cyl) doubgle race springs, 17110-12 valve retainers 1.7/16 (6 cyl) and 11703 single groove (6 cyl). i have alreay got a ported polish manifold. i have extractors, cai and 70mm throttle body. I was going thinking of going for 1.90 roller rockers and will be getting either stage one or stage 2 shift kit later.