Just mounted a evolution .52 in my sky raider mach 1 i did all the measuring according to the instructions everything was even looking and same distance hangover on the mounts on each side but to get the right distance from the firewall i had to set it way out on the mounts so after about an hour and a half of looking, fitting, wondering and worrying i went ahead and drilled the holes it all looks good but is there anyway to be positive that i did it right before i bolt it down for good?

"Way out on the front of the mount" is normally the correct place. The only concern that you really need to watch out for is that the two front holes tapped into the mount are far enough back from the front tip that there's no concern about breaking or cracking.

After that, it's simply a matter of balancing the center of gravity (CG) and possibly shimming the engine mount a bit if you notice any upthrust or left thrust when you test fly the plane.

Hi,
theres a couple of things to add to bigedmustafa's good advice.
test it with the prop on to determine cowl clearance (if there is any cowl).
Also balance if the rest of the plane is all together.
be sure and test each nut and screw for tightness before mounting such as back plate screws use lock tight on 'em if you want.( the stuff that comes appart not tough stuff.)
check the carb mount screws and muffler screws too.