Symptoms of an Intake Leak?

BIG thanks to TXDart!
We smoke tested the crankcase with and without the carb and found the intake is sealed, but my Holley was leaking at the throttle shaft. Swapped on an Edelbrock 850 and the idle fluctuation went away.
We ran the car and it ran much better until we got back to the shop. We initially used a standard thin gasket, and with the guage still getting to 225°, heat sink boiled the fuel. The fuel was puddling on the butterflys, then spewed out the bowls. We cooled it down and tore down the carb. Martins carb had only been used for break in and had been sitting. We found trash in the bowls and determined the boilng stirred it up, preventing the passenger side needle from seating and/or sticking a float. We cleaned and blew everything out, checked the float travel and levels, and added a very thick fiber gasket.
Took it back out and drove it about 15mi roundtrip under varied conditions, back road cruising, highway speeds, and hard acceleration. It peaked out at 225° and throttle response was great. The motor seemed much more tame and streetable. Very smooth lopey idle, and a monster when I gave it as much as half pedal. I didn't go nuts due to darkness and unfamiliar roads but no trouble breaking the tires loose at 30-40mph, and from a stop it will spin the 275's until I let off.

Not perfect but a HUGE step forward.
Next steps will be Countour fans with a Dakota Digital controller and then maybe a Champion radiator. Also will be adding a Wideband A/F meter when funds allow.

Really appreciate all the help and advice. Without all the good people on this site would have never gotten this far.

I have to really give Martin a big thumbs up! I met him here and over the last year we have become great friends and he has selflessly spent his time and resources helping me out.