340 has a hard time starting when hot?

I wouldn't think it would be. If it starts as you say good that second time, I wouldn't think the cable size would be the problem. I would be looking for a connection loss somewhere. How many grounds do you have on it? Such as from the engine to the chassis and firewall and such?

alum. engine plate, fore and aft engine limiters on each side of the block, small
braided ground strap on pass side head to firewall. GROUNDS ALL OVER THE PLACE /TRUNK MOUNTED BATTERY IS GROUNDED TO BODY BACK THERE , BUT THE F.INJ. IS GROUNDED CLEAR BACK TO THE BATTERY. wouldn't THINK IT WOULD BE A GROUND PROBLEM. ?? DISREGARD CAPS , CANT KEEP MY CLUMSY *** OF THE CAP BUTTON ! lol