help Clutch fitment for 67 chevy inline six

[bluechevy67]

I have a 67 chevy c10 pickup that currently has a 10 inch dia X 1 1/8 X 10 sline clutch disc and pressure plate mounted on the flywheel. Does anyone know what other clutches will fit with the orriginal flywheel. The truck has the original 250 engine and three speed transmission. Ive visted many clutch websites and all of them carry 10.4 and up dia clutchs but no 10 dia(unless its a ford 10 inch). Does any one know of performance clutchs for this set up? Also what is the orriginal clutch size?
Any clutch types, brands suggested?
Ive measured from where the current 10 inch disc has polished the flywheel(at the outer edge of the polished ring) and at the edge of the polished ring their exist an half inch before the clutch mount bolt holes.

Any help would be greatly appreciated.
thanks,

robert