Won't start, What do you think?

[gipper]

My truck has set all summer (bad, I know). I have a 1968 GMC stepside with a 1972 chevelle 350 engine. I installed all new Universal joints and a midshift bearing this past winter. When I was done, I ran the truck (On jack stands) for about 15 minutes. I tried to start it last week and nothing. I had it on a trickle charger for more than 24 hours still nothing. I pulled starter and brought to local parts store and had it tested and it was fine. I double checked all wires and they look fine, connections are fine with no corrosion. I am not 100% sure I put the two small wires to the solenoid on correctly after re-installing starter. Do not know if that is an issue. I checked the ignition plug and it seems fine and the red battery light comes on when I turn the key. I am stumped as to what else to look at. Any help would be appreciated.