Starting problems

Hey guys, so I just completed a 318 to 360 swap and I've yet to get this thing started. (Once I fix one thing another comes up) but while trying to get my car to start my battery went dead so I got it charged when I got it back in nothing would happen. No clicking or anything. With the new starter in I tried doing the screwdriver trick, it sparked a little bit and engaged for a second, then after that nothing.

Things that I've done so far are; switch out starter and and test voltage in wires with a multimeter. Pretty much they all read 12.68 except for the small thinner wire on starter. I've checked fuses and a couple were blown so I replaced them also.

Any guesses as to what the problem is? It's just strange that it was turning over engine one day and the next I've got nothing.