An ebayer says these fit big block chyslers? From tore up bulk box from federal mogul. Says these are for a small or big block when you bore the lifter holes, using a hot cam. 610 end to end of roller. 510 lifter housing end to end.This item is in the category "eBay Motors\Parts & Accessories\Car & Truck Parts & Accessories\Engines & Engine Parts\Valvetrain Components\Camshafts". The seller is "vernsdog" and is located in this country: US. This item can be shipped worldwide.