360 timing questions

Since you say the heads have been cut a bunch but you don't really know how much it's quite possible your compression is closer to 10 to 1 so 87 octane is not nearly enough. I'd put in some 93 octane before you blow the bearings and/or pistons out of it. Detonation is very destructive.

BTW: shimming up the rocker shafts .045" is not the right way to correct for all the milling that's been done. To do it right you need to install shorter pushrods. When you shim the rocker shafts up you also bring them closer to the valves. In doing so you throw the valve train geometry off. You can get away with a minor amount of shimming them but I personally don't like to go over .020" at the most. JMHO