came only on the 325HP Manual trans 400 Firebird, 360HP Manual & 376HP Manual/Automatic trans 428 B-body, 360HP WS
code & 360HP XS
code Ram Air Manual trans 400CI Tempest & GTO....
Jim, I'm not sure where you are trying to go with the Firebird carbs. the early Firebird Qjets were only used on Firebirds...had the limiter tab. The OP asked about '67 400 HO GTO carbs. I incorrectly noted 350hp as the base '67 400 4bbl HP notion, FORGIVE ME, I've owned many '67 GTO's...what I was trying to convey is the '67 49 state 400 engines, code YS & YZ used the exact same carb, the #7027262
. It was also used on various '67 B series with the 428. No holes were original in the original primary throttle blades. ,on this particular Qjet, the 7027262, the original anodized alum ID plug was a bright blue. Likewise, the 49 state usage '67 WT & WS engines used the #7027263
Original '67 CA usage 7037262's & 7037263's were also built by Carter. Again, both were used for base 4bbl GTO & HO GTO engines...just CA emission engines. Two of my good friends are currently restoring '67 400 HO CA emission GTO's, one is a 4sod Post car. Many times, one will run across a 7037262 Service Repalcement Qjet made by Rochestor. That particular Qjet is not that valuable, & one shouldn't overpay for one.
Also own Cliff's extremely well written Qjet book, as well the much earlier Doug Roe Quadrajet book. First modded Pontiac Qjet builds i performed were over 35 years ago, when over the course of a few years ordered well over half a dozen HO Power kits from HO Racing... Finally figured out several of HO's carb recipes & how to order the same metering rods, jets, & power piston springs from local dealership.
Around '82 first began pulling divorced choke ('67-72) Pontiac V8 Qjets in yards, eventually buying them by the mid '80's @ swappers & through two rebuilder contacts. Even in the early '80's, the divorced choke Pontiac Qjets were not that easy to find on cars setting with the hoods down, even in monster country yards. Often these original divorced choke Qjets had prev been pulled, many times ending up carted off in core barrels, or setting on a dirty dusty shelf.
On the '67 Carter built Pontiac V8 application Qjets, one has to be careful, there were reproduction alum tags which came avail just a few years ago, may still be avail today...I dont know. Not good, as several fraudsters bought them & have been creating fake '67 GTO Quadrajets.
To the OP, all I can further mention, is like Jim alluded to, often original Pontiac Qjets have been disassembled & reassembled with different throttle body's, different airhorns, also universal jetting. Many times, the '67's and '69 & '70 Pontiac V8 Qjets have had the '68 vac port added to the passenger side of the throttle body. Nearly all manual trans Qjets that made it to mass rebuilders gained an oversized port for an AT carbs Vac modulator line. With the right processes many of these problem issues can be remedied. Hope this helps.