Thanks, NTX. NASCAR teams essentially blueprinted the engines, and incorporated petitioned modifications. In M-1's case, that meant use of the thinner Dynaflow headgaskets and DF camshaft in front of the conventional transmission. They also honed the cylinders a few thou, polished the bearings, matched gaskets, and otherwise loosened up the engine. Red Vogt also shortened the pushrods, which makes a lot of sense in concert with the thinner headgasket, but that's what they ultimately found to disqualify the car for. Read the whole story at www.FireballRobertsM1.com. Chassis-wise, NASCAR mandated a frame-mounted steel rollbar or cage, and I'm trying to find out if they allowed bigger brakes and hubs. Were 50/70 brakes and hubs larger? Would they bolt to a 60 Century? I'd like to know the answer to that. Marty, I'd like to acquire those rocker arms if you think they are correct. If I can find the cam specs, I'll have a stock one reground. Cup-type lifters ... ? What else fits? Also, does anyone have the definitive conversion to an hydraulic clutch actuation set up? Keep an eye out on www.FireballRobertsM1.com, here and on the Yahoo Nailhead group page for progress on M-1. Josh