Well I just got the 455HO up and running in the world's most expensive run stand: I ended up bolting the engine and trans back in the car and hooking up the basic wiring and a tach, oil pressure and a temp gauge. No exhaust, just a couple of dump tubes off the exhaust manifolds. I tried using my mechanic buddy's rubber exhaust tubes (the ones you use in the winter to pipe the exhaust out of your shop). They didnt help one bit. In fact the exhaust coming out of the manifolds was so hot it set the insides of them on fire.
Very scary for a few minutes -it looked just like a blown head gasket: billowing white and grey smoke out the pipes. I yanked them off the engine and the smoke disapeared (along with the crowd of neighbors who gathered to watch my garage burn down). I let it run between 1700 to 2500 for about 25 minutes, I changed the oil and no metal was on the magnetized drain plug. I let it cool down overnight and it started with a click of the ignition key this morning.
So it all looks good for now. Now I can pull the car completely apart and store the engine til it's done. This thing was so loud I had to use my industrial ear protectors!
