340 with edelbrock heads overheating

RogerRamRod said
IIRC my initial is 18 and I have the FBO plate dropped into the 14 slot giving me a 32 total. I am just getting started, & expect to tweak it some. I used a vacuum gauge to get the initial, this was how someone told me years ago, but I had to search around to remind myself, had been out of the car game for a while.
Gauge connected to manifold source. Make sure no vacuum leaks, vacuum advance disconnected and plugged, Advance timing. Each time RPM & vac go up, reset RPM back down & repeat. once you reach as much vacuum as you can, back your timing off a couple degrees. Probably find yourself close to 20 somewhere.
34ish seems to be a good starting point for TOTAL (this is NOT incl. vacuum numbers yet), so - Subtract your new timing from 34, and that is the # slot on the FBO plate to start with.
#1- Listen for any pinging, dial it back 1 or 2 before going any further

I didn't like the FBO plate. It's not accurate. I had to use the smallest slot (10 degrees) and was still getting 16 degrees mechanical. That's just too big an error margin. I pulled it back out, removed the distributor governor and welded the slots and filed them down to get only 10 degrees mechanical. So now I'm at like 20.5 initial and 30.5 mechanical. Slant sixes don't like much more than about 30 total. Yall need to check these plates with a GOOD digital light though, to make SURE you're getting what the plate says, because I was not.