Originally Posted by F-BIRD'88
You only need to richen it up a bit. It won't surge.
Do not attempt to target a particular AFR at idle. Give it what it needs.
Surge at idle is real fat or real lean.
Do yu have a boost retard box? if so set the timing to 34BTDC and take timing out as boost rises, with the box.
Here's the fun for tonight (I actually do enjoy carbs, they make me THINK!)
Took some 18 gauge wire and stripped it to individual strands (tiny). Put one strand in each idle air bleed and bent over the edge of carb so they would be held in by the air cleaners. Started car and warmed it up. Car idled rough so I had to back all 8 mixtures screws out 1/8 more. No blower surge. Checked the AFR and Aha! A difference, although only .4 AFR. But the misfire at 2500 was reduced. Added one more strand to each bleed and now the IFR is down to 14.9 @ 2500.
So I ordered the Proform kit that has bleeds from 65-75. Bet I'll be using the 65's but it is just a hunch.
I could probably up the primary jetting but I already have 79's in there and a 6.5 power valve. Hard to believe 650's would need more than that?
When I power brake it against the convertor the AFR drops to 10.5 so I am plenty rich already!