Thermoquad Wanted
I just saw one at the local swap meet this past Saturday, new in the box $15. I didn't think twice about it because those things were junk outta the box anyway. Go with an AFB or a new Edelbrock, don't waste time on warped plastic.
I wouldn't say that ethier. I have several T-Q's (2- 800 cfm, 3 850's) and 2 Carter 9000 series (625 & 750) AFB's, not Edelbrock carbs, 2 OE AVS carbs (630 a& 750) And just got back into a Holley again after a long time of not having one.
Leaving the Holley out of the comparo, the T-Q is the fussiest to set up. But it delivers the best & most W.O.T. performance and is the nicest street manored of the 3 Carter model carbs.
The AFB is the softest on performance with correct sizeing being most important. I can and have gotten a 750 to work on a mostly stock 318 without much problem tuning it to work. And work it did. But it was soft on acceleration until the engine got the RPM's up enuff to strart making use of the large carb.
The AFB's weighted secondary velocity valve is heavy. Which is good for big cars. Weighty B or C bodies. On a 318 Duster, it wasn't so hot. The doors need to be lightened. A lot.
The AVS being very similar to a AFB but having the spring loaded secondary door is real nice. I dialed it in to open faster than the AFB's doors would open and a noticable difference was felt. The butt meter said OH YEA! Theres more power!
Same as above for the T-Q except even more power and drivabilty. The 800 unit is the one to use on a stock mild teen to a hot street set up.
Tuning the Holley as we speak, I came in for a break.