[Jeff Chambers]

Maybe misalignment between trans and flywheel binding the driveline? With new clutch did you install a new flywheel? Could be too tight between the flywheel and starter. Also, be 100% sure of your timing. I've seen it before on balancers with four sets of timing marks where the wrong set was used and the car cranked/fired very hard. At the time, it looked like a battery/starter/flywheel issue but it really came down to the car trying to fire at the very beginning of the compression stroke. Cylinder pressure was fighting the starter.