Does anyone have any experience in sourcing one locally - block, pistons, long stroke crank, rods. From TRS or Bruce Davis or out west? Are they top hatted? Cheaper than from V8 Developments, D&D, etc?

I'm thinking of treating my SD1 - currently fitted with 4.6 with BV Buick 300 heads, Supra box, etc. Then putting the 4.6 into the Disco.