Holly Carb 4150/4160

[67fb390]

I recently purchased an original (rebuilt motor, not carb) 67 FB 390 that was in Canada, I put 93 octane in it for the first time and the carb freaked out. First it would barely idle, ran it around the block and it somewhat cleared up. Now it is running really rich with some slight smoke from the exhaust. I have readjusted the float levels, the air/fuel mixture, and curb idle but it is still too rich. Prior to putting American fuel in it, the previous owner was using 94 octane and it ran beautiful. Something in the carb has popped, any ideas would be appreciated.