I was looking through the Summit Racing catalog; there might be parts shared with V8 engines. I noticed similarities regarding the hydraulic lifters (same diameter) and piston rings, and possibly the valve springs. I'm currently trying to find information on the crankshaft bearings—specifically, metric dimensions for the main bearings and imperial (inch) sizes for the connecting rod bearings. for V6 and V8 https://www.summitracing.com/parts/mel-jb-7003
They all have the same 0.842-inch diameter as the X-Wedge; the height without the roller is 53.4 mm (56.6 mm with the roller), and the ground height for sliding contact is 38.5 mm.
MMC are having some parts remanufactured. I understand full engine gasket sets and pistons are available and crankshaft bearings are on order. Hopefully there may be other parts coming.