What clutch were they running and had issues?
On my Chevelle, I used a McLeod twin disc set up. They claim it'll handle 1200hp or so, so I figured it could handle my 496,
.
I didn't have the car long enough to really test it much. It felt and left like a stock unit IMO, no drama.
The damn thing cost like $1400 bucks though.
I'd look and see what SPEC, Centerforce, Fidanza, and Hayes has to offer. I know they all make a flywheels for T56 to sbc/bbc.