Its me again lol

Like we talked about in your other thread, you might need more initial timing (to bring the idle speed up and be able to close down the throttle blades and square up the transfer slots) but you can’t do that yet because the mechanical advance brings in too much timing and it rattles. This is all part of tuning. You need to limit the mechanical advance in the distributor and bump the initial up a few degrees. Then test, and do it all over again.
Well, he can do it to see if it will solve the crappy idle issue. At least then he'll know what it needs. Sounds like it's getting too much too soon. Sometimes heavier spring(s) will solve it by themselves. Sometimes. lol