Timing should be around 7 degrees BTDC with engine idle around 650 and vacuum line to distributor blocked off...
Heat soak on starter...assume you have tubular headers and old large format starter....do all items for best results...
1/ Wrap exhaust pipes close by the starter with heat wrap.
2/ Mini starters move the starter body a little further away from heat source...
3/ Make sure your battery cables are sufficient gauge..and you have good grounds between engine and chassis and battery....clean the chassis really well with wire brush and sandpaper where cables need to ground.
4/ Add a heat shield to the new starter for added insurance....
Have fun...
