My truck is hard to start when cold and hot. What have I done?

Hello. I have a 1978 Ford F150 w/ a 302 2bbl. I had a new engine put in it in 2004 and only have about 6500 miles on it. I just had the carb professionally rebuilt due to the truck being hard to start when hot and bogging down when accelerated. I put the carb on and it started fine. Went to drive and it is still bogging down and still hard to start when hot. I checked plug wires, coil, air cleaner, distributor. During the check, I have done something very wrong and can’t find what I did. The engine is now hard to start when cold. It sounds like it is just about to start but won’t. After several attempts, smoke is coming from carb and smoke coming from oil valve cover vent and oil dispstick. I let it cool and it will finally start and once running the smoke goes away and it idles fine, except for under load. Still hard to start when hot. Now hard to start when cold. Can somebody tell me what I have screwed up? Thank you for your time.