Need help with rebuild

Your problem could be so many different possibilities. If it won't start with starter fluid, but sputters, I would check timing, ignition and valves.
When I rebuilt my slant some years ago, I had 2 different problems which prevented the initial startup. I had the wrong year harmonic balancer which showed the timing as correct, but was actually off by about 60*. Also, I got platinum plugs which fouled way too easily and, with a new 4 bbl, that happened almost immediately.
Keep us posted and good luck!