A few oil related questions/conserns.......

[Excaliber]

It is somewhat common for a carb engine to get a little heat soak after it sits about 5 or 10 minutes. Just long enough to fill the gas tank, put the cap on, pay, walk back to the car, and then hard to start (CRANKS fine ). Could be some gas boils over or evaporates and leaves a "fog" in the carb barrels, thus resulting in a somewhat flooded condition. The extreme end of that would be like KC mentioned, float to high and serious flooding is the end result.

Something I've found that helps to address that problem is to make sure your running enough BASE timing to begin with. Most often I see "hot rod" type motors (big cam, after market this and that) NOT running enough base timing. "We" get scared and worried that if it's to much it might ping,,, it won't. Ping, generally, has nothing to do with BASE timing, PING (detonation, knock) is typically induced because your mechanical advance advances the timing to far in ADDITION to the base timing. To far or possibly to fast, but really, to far is the primary concern, to fast is not generally a problem. Not fast enough is more of a problem!

So how do you know how much base timing you need? One method is to advance it until the starter motor has a hard time CRANKING the engine over. When you get that, then back off the timing "just enough" so the starter can crank it nicely. Myself, I run about 20 degrees base timing, 22 makes the starter grunt, it's that close!

Typical timing setup is something like, 32-35 degrees TOTAL (base plus mechanical advance) "all in" by say 3,000 rpm. Myself, I like it to come in sooner and I run it higher, 36-38 total. But OK, I'm not all together normal (but I am fast)!

If it were mine, I'd bump up the base timing just to see if it improved the hot start condition if nothing else.

Important foot note:
You may have to buy or have built a special mechanical advance stop "button" of some kind to limit the maximum allowed mechanical advance IF your running a lot of base timing to begin with. 20 base, plus the typical 18 mech advance for an MSD is a total of 38, might be to much for YOUR motor. You either have to custom modify the MSD distributor OR run less base advance. I modified the MSD distributor on my engine to get what I wanted...