ALL ENGINE REBUILDERS, and INCLUDING ME, MY OPINION: There is no way, a rebuilder should have to run an Engine to check his work. It really tells you nothing anyway. I have seen Rebuilt engines on U-TUBE running with just a garden hose poked in the head, boy that does alot of good on a rebuild, and the video says, just listen to it Purr. Wore out engines that need rebuilding will purr on an engine stand, but in a car, won't get you across the street. Now, MOTOR TESTING, should start with a Clean, well machined block, and every subsequent part, or operation after. Just because you have new, or rebuilt parts, DOES NOT MEAN THEY ARE USEABLE. They all have to be checked. I don't care who has rebuilt an Engine, there is NO Excuse, EVEN ONCE, for valve sets coming loose, piston sleeves down around the crankshaft, pistons stuck, or scored, Babbitt, or inserts going bad, cracks missed, valves leaking, Head Gasket because of improper decking, Flywheel housings out, along with every thing else. One thing many don't think about, if the shop you use, has a cylinder boring machine that sets on the top of a block to bore cylinders, and if it was made in the 40's up, and has never been checked for trueness, there is always a chance it is not. Those kind of portable boring bars are as good as any boring bar made, PROVIDED, THEY HAVE BEEN CHECKED FOR TRUENESS. These kind of bars, such as a Van-Norman, normally get, drug, slide, pushed, across the floor, tables, blocks, ect. and that destroys the hand scraped surface, that will let the bar bore from a flat true surface, at a 90 degree. The real big problem with these bars, are that Model A's, 90 %, and up have have been decked before in there life time. The most common surfacing machine was a Van Norman. It was about 6 ft. long, a maybe 12" grind stone in the middle, and both ends looked like a kitchen sink drain board. When you slide the block, and or heads across the grind wheel, it will deck the surface all right, but it was not necessarily running with the pan rail, so Boring cylinders at 90 degrees got lost some where. I have seen many of these surfacing machines, and some were wore, a 1/2 inch on the sides, and they were still using them. Herm.