The engines were bored, sleeved if needed, line bored if necessary, crankshafts reground and balanced, rods reconditioned, rocker arms replaced or reconditioned, and generally brought back to factory specifications or better. They offered a 2 year, 25K mile warranty, with extended warranties available at extra cost. I installed dozens of their engines, and only had problems with one, which had a camshaft ground out of spec by one of their suppliers. They sent me a new cam and lifters and a gasket set, and paid my labor to swap the cam.
Several big rig tires were bolted together into a long tube on a rotating fixture, and the blocks and heads were tumbled inside to shake the ash from the baking process out of them. It worked very well. Grooms Engines started out as a speed shop in the late 1960's, and by the 90's they were turning out 30-something rebuilt stock engines per day. Roger Grooms retired and sold the business to some yankee outfit, and the quality took a nosedive. I quit using their engines after that.
