starters keep getting to hot need help

Initial timing, NOT TOTAL. What's the timing at idle if it has any curve in the distributor.

GROUNDS. When batteries get put in the trunk, the grounds at the engine get overlooked. You need a good sized ground from block/starter to the frame or another big ground cable back to the rear.

If your 340 did the same thing, I'd bet you have insufficient grounds. I have battery in trunk, and put 2/0 ground from engine block to frame rail. Nuts welded on frame rail to attach. Also have 2/0 starter wire.

Take a pair of LONG jumper cables, attach both of them to the block and then back to the battery neg post. Basically creating another pair of ground cables. See if it starts easier. If it does... you know the issue.