yeah, it's not rocket science, so don't skirt the obvious. just doublecheck the distributor. pull the cap leaving the distributor in, and rotate the crank to TDC, just to see exactly where the rotor is. it should be right around where the #1 point is. if you had it out 180, it wouldn't even start, so you're probably in the right spot.

and you've got your valves set correctly too, right?
you can do a quick check if you pull the valve cover again with engine at TDC -- just give the appropriate rocker arms a quick wiggle to make sure the right ones are loose and the others tight, then rotate one full turn on the crank and check the rest the same way.

if you've got it running at 45* BTDC I should say it would run hot! along with the other symptoms you mentioned.

let me ask you this -- when you put the distributor into the head, do you already have the rotor pointing at #1, or does it end up at #1? it's supposed to end up at #1 after you put the distributor in. to get it there, because it rotates, you have to insert the distributor with the rotor about vertical, then it rotates CCW to about the #1 position. this is what you're doing, correct?