New to Holleys. I've just put a six pack on the engine, and A/F at WOT is in the mid-low 12's, cruise at low 13's. Seems ripe for a jet change. I have 66's in there now, and a set of 62's, is that too far to go to try and move that WOT up to about 13.0:1?
With all the comments in your initial post,unless I missed it you never stated what cam,as far as 62's I think you will be lean with a 540 cu in motor at WOT.As far as what Cab posted,the replacement carbs are exceptionally lean and I think you stated you never did anything with the outboards.
