I have a few question and need some help.

1)What is the best year of carb to use for racing?

2)I am building an '81 and am having some carb related problems. The motor is fresh and was running good, the carb needed some tuning, but near the end of my first short drive, I let off the throttle and the rpm shot up to 5k.

The guy I bought the car from (also the engine builder) recommended I remove the dashpot. I did, but it didn't help. It looks like the throttle cable had some slack, but the throttle appeared to be closed.

So I removed the carb and stared at it for a while. Assuming that didn't help, can anyone please give me some advice.

I don't know what year the carb is from, but the top of the primaries is larger than the on the one from my '83 parts car (which I was told needs rebuilding).

Thanks