[1320racer]

before you say the floats are fine do this...remove the bowls, invert them and slide a 3/8" or 7/16" drill bit along the roof of the bowl and the top of the float, adjust as necessary.

As to the transfer slots...take the carb off, turn it upside down and look at the slots that are in the wall of each bore. The baseline setting should be about .020 measured with a feller gauge and they should look like this [ ], partially covered by the throttle bore blade(s).

After checking/setting the floats and transfer slots, reinstall, set idle mixture screws, then set idle screw.

7 1/2 is to much, lower it to 6 1/2 for a baseline. If your fuel gauge is liquid filled, get rid of it.

Just confirming, you have no mechanical advance in your distributor?