I was planning on running premium fuel, which around here is about 93 to 94 octane, although it will also contain ethanol at about 15%. I will certainly see if I can find one of those timing lights. I don't mind paying for features in a tool if I'm actually going to use them. As far as timing, I'm hoping the stock 10 deg will be ok. If not, I'll either dial it back to 9 or bite the bullet and get a thicker head gasket. The engine builder seemed to think it would all be OK, and they had built a fair number of L engines for satisfied customers. I'm really hoping they were right.

If all else fails, I do have a spare engine out of a 280ZX that was running fine when I bought it. I can always put that in if I need to.

You should try it! worst case scenario, you could always purchase the parts required to solve the potential issue.