Electrical problems

What you say about the later start relay is true, and if it is only giving you 9.5, then you need to check right at the battery when cranking. If the battery is "let's say" 11 and the relay 9.5, you have a gigantic voltage drop somewhere

Having said that, the later relay should not be needed. I would not stray too far with modifications, that is,some of us have a saying, "fix what is there." What that means is, it did work, and sometimes making mods can ADD problems and REALLY throw you off

Did you try "hot" wiring to the coil from the battery?