I hate to rock the boat, but I dont see much wrong with what you have except the timing curve in the dist, and maybe too high a static ratio for that cam. The SD is a great all around intkae, and would have been my 2nd choice. First choice is the Performer RPM. The SD is a smaller port single plane, with a med sized plunem. The M1 is larger port, larger plenum, and wouldnt have even been in the running if I was putting the package together. The cam is fine, the pistons are ok. Mayeb too much static, but I'd bet the over heat problem was the lean and retarded timing, and the lack of power is the timing and carb. The Demons can be a bear to tune, and BG has good tech guys, but you need to know how carbs work before you can really work with them. There's a couple books on that. Buy one. The MSD dist has 8 possible curves soley based on the springs they provide. Total centrifical is done with a bushing. He put in the 20° bushing, and I'd wager has the two light springs in it. You should be running a heavy silver, and a blue for springs. That will slow down the advance so it doesnt go into pinging as early. Total is what the engine likes, and can take, in that order. If it pings after adding the spacer gaskets, you'll have to address the static compression issue. I doubt it will, but a slower advance curve helps cars with pump gas, higher rear end gears, and stock or low stall convertors. It should pull and run fine iwht teh stock convertor, but it may "thunk" into gear wehn going into drive. Instead of replacing new stuff, try sciencing the setup out first. If there were only one or two good parts for every application, everyone would have the same thing. You can make what you have run well, and then if it's beyond physics to run on pump gas, you can make a change. I dont think it will be an issue if it's all sorted out properly.