Got a 73 Mustang with a crazy 351w someone put in instead of 302. Runs incredibly fast and came with all kinds of goodies. Performer RPM aluminum heads and roller rockers, Holley, MSD dist and 6A box, ceramic headers, tubular front suspension, etc. Runs hot, very hot. I put my hand behind the fan while idling and in seconds my hand cooks. The gauge doesn't show hot until I turn it off. Try to start it again and it turns over agonizingly slowly. Initial timing is 5 degrees advanced. If I back off more it turns over more easily and runs cooler but less power and slight backfires. Feels like it is the timing because it runs cooler by adjusting the dist. Has a huge aluminum radiator. Clutch fan. Any thoughts? Thanks.