I want to swap out the AFB (newer Weber version #9635 with Mopar linkage adapter) for a TQ. I have a Performer intake so I can run either.

Combo; '83 D 250 (3/4 ton 2WD) daily driver, 318, 727, 3.55s, engine has stock 360-2bbl cam, (dang close to COMP 252) EQ Magnum heads, Hooker Super comp headers and true 2-1/4 duals all the way out to the bumper, and the Performer/AFB.

I have 2 #9265s TQs here, that I had rebushed and I then kitted. OE app is 80 truck 360 on these carbs. I have my suspicions as to why, but neither carb ran worth a S#!T when I test ran them on my engine. (maybe an answer to my own Q here) but I am thinking of sending 1 or both to DemonSizzler; but they both run the same; mixture screws all the way in and still seems rich, one seeping fuel between the bowl and top casting (airhorn). About 30 min run time total combined between the 2 TQs since kitted..
Would I be better starting off with a early-mid 70s TQ instead of the '80 model?

Back when my brother HAD an 80 360 powered Ramcharger (for which both my present carbs are the exact OEM application) I could not find "these" carbs and built-up a 74 440 Cali version.(what I could find at the time) On that otherwise stock 360, that carb ran great! and passed smog here in IL.

(where I now live in IL, smog is a non issue; I just want the thing to run right)
It don't run "bad" with the AFB at all I just think there's more to be had with a TQ based on other TQ equipped smallblocks I have had before.

so these I have would be better than starting with an older-spec carb?

Not sure on that but I'm thinking that the 80 ones probably dont have ported vac (& the earlier ones may not either) which is preferable in most cases. On your deal I'm wondering if the bowl is warped. EDIT worded that backwards, meant to say ported is preferred (most cases)

yeah these do have ported vac ports; this carb is "FEDERAL" spec not Cali, the RC annd the van I got them off of (same day/same 'yard) both had "regular" electronic ignition; with vac advance.
I do remember something about "restrictors" in the idle mixture passages on certain year carbs. (something I read somewhere)

I know everyone's impression of "reman" carbs but tehers been a few 72-3 340 ones on FeeBay lately that I have been debating on buying as a starting point. (I bid on a couple but not very high, being I knew I had these 2 already)

I've always "heard" that these carbs had bowl issues, but have always READ that they did not. Rarely, (RARELY) did the plastic bowl if ever, warp. (maybe engine meltdown or major fire?) it just didn't happen. people placed blame where it didn't lay, mostly due to their lack of tuning skills. People just didn't take the time or effort to adjust them in the correct procedure. If you try to fix "point c" before adjusting "point f" you are going to have problems and will never get it sorted out. it must be done in order. A,B,C etc. Demonsizzler is the man to go to, from everything I hear and see.

Have you rebuilt a TQ yourself before?

If you 'double stack' or put the wrong o-rings (too thick) in the wells you will effectively raise the top causing all kinds of problems.

Is the float level set correct?

Reseal the jet wells?

check the wells for leak

I DID reseal them; 1 was off the bowl on each carb as I took it apart; Super Glued them on and used a product (suggested by D.S.) called Seal-all to (try and) seal them up; from the other recent TQ thread I'm wondering if it isn't my needles/seats.