Thermoquad vs holley vs q-jets

RRR, Dana,.
Thanks for the info.
I have that info but wondered whether your info was different to what I already had.

Couple of comments/suggestions. I have used TQs since the 1970s.
- never had to enlarge the IFR to 0.052." That is a huge increase, more than double the area of the typically stock 0.033" IFR. 0.040" is largest I have needed.
- 4 or more turns out on the mixture screws, I would be enlarging the screw discharge holes in the bore.
- the later 9000 series carbs that bypass air routed from the air horn to under the base plate was to avoid nozzle drip which could occur if the air passes down the t/bore. I have seen earlier 6000 series carbs that had the base plate drilled for bypass air; have also seen the pri blades drilled. Both methods means air is passing down the t/bore & could induce nozzle drip.
- best way to avoid n/drip if more idle air is needed is to drill the secondary blades. Engine doesn't care how it gets the air...
- have never touched the IABs & have never had a need too...
- occasionally, the idle down channel which supplies the T slot needs enlarging. Very hard to get at on the TQ. It is a brass insert in the a/horn about 1 3/8" in from the surface, so long drill bits needed.
The said 451 still had booster drip @ .120 IBP, @ .125 it still spit fuel intermittently. @ .128 the booster drip was completely gone. At that point, in order to keep the Idle mixture screws 1 1/2 turns from bottom, the IFR’s had to be@ .052. I didn’t dream that size up. I listened to the engine and gave it what it asked for.