I have a 67 Firebird 400 that has had a pretty much complete engine rebuild. Bored, new pistons, push rods, cam. Edelbrock intake manifold with a Cliff Ruggles rebuilt quadrajet. Runs great for about 5 minutes until it gets really heated up and then wants to bog down on the top end and is difficult to restart after being shut down. It seems the carb is getting awfully hot. I've been told that using a 3/8-1/2" wood spacer to get the carb off the manifold will cure my problems. Any other suggestions?