Thermo-Quad metering rod measures

Bewy said
[1] Mecki, you are over thinking this.

Yes, I probably do over think this (as I often do).

Bewy said
[2] The tube in post #34 has probably been added. Some TQs used that port for a hot idle compensator. Somebody may have used that carb with a huge cam that needed a lot of bypass air, & used that hole for bypass air.

That's a reasonable explanation for that tube. It would probably do more harm leaving it open on a relatively stock 440 with A/T or?

Bewy said
[3] I have only ever found two sizes used for the sec high speed air bleeds. Early carbs used 0.039" along with big jets [ like 0.149"]; some later carbs used 0.029" air bleeds with smaller jets [ some had 0.098" sec jets, smaller than the pri jets. Go figure! ]
[4] I enlarge the sec air bleed to 039 on all TQs & use the bigger jets.
[5] Some later TQs had 0.101" pri jets, buuuuut they also had larger air bleeds. not sure why, presumably for emissions.

Bewy said
[6] I would NOT be using AFB rods in TQs. first, you would want to check to see if the total travel of the rod is the same for the TQ & the AFB. Probably isn't. Also, the power step on AFB rods is usually longer than on the TQ rods, so a fundamental difference there.

Ok, thanks for that information. Luckily it looks like the rod problem is going to be solved.

Bewy said
[7] Since you have the carb apart, you may want to do the mods I listed in a thread in this section in Oct 2023. Those mods will make a veeeeeery noticeable performance improvement. On a 440 that I built for a 68 Charger, 5 speed man, TQ modified as above, it spins the wheels in 3rd gear when the secondaries open....

I suppose that 440 was nothing but stock. I will look for that thread.

Thanks