King race bearings equivalent
I have sold several 408" (360) Stroker kits with King MB517XP Main Bearing & King CR805XPN Rod Bearings this year and I've had no issues in getting the bearings.
Only issue I had this year with King is they no longer sells a reasonably price 340 main bearings. You now have to buy coated bearing which are double in price.
Otherwise I've had no issues with getting any bearing from them.
Tom