Thanks for the reference. I might have found a simpler solution- - - - -how about turning the bearing journals down on a 261 cam so it will fit into a 216 block? My Federal-Mogul bearing catalog shows that there's almost exactly 1/8" difference in the journals (all 4 of them, even though they're different sizes) so that means taking 1/16" off the radius of the cam journals should allow a 235/261 cam to fit into a 216 block. I've got a couple of junk 235 cams, and several 216's sitting around, and it won't be difficult to fire up the lathe and the tool post grinder to do a little experimenting. If I can get a cam and a block communicating with each other, then it will be time to check on such things as piston/valve clearances, etc.
Jerry
