Snowman, If your WOT mixture is correct then measure the 73 jet with a drill to get diameter, then measure the PVCR dia. figure both areas add together to get total area. Take about a 66 jet and figure that area, subtract from total to get area to drill out PVCR, install a 2.5 power valve. Turn in idle mix screws all the way in then out 1 to 1.5 turns. Set floats so gas drips out at idle. Set pump shot so there is a little pressure on the diaphram.
Set total timming to about 34*, if you have 22* cent. then set initial to 12* with vac. off dist. and hose pluged. This is not too much with 15# boost. Set timming before tuning carb.
If fuel system is up to par should work.
Do not drill any air bleeds.
Harry
PS make sure the transfer slots are not exposed or drill a small hole in each blade.
