This may seem like a stupid question but I would like to know what is the difference between a 6319S and 6318S Thermoquad. One is for an auto car and one is for a manual car both 1973.

I have at least one of each and they are rebuildable. Not sure on the resin blocks are they interchangable?

I believe so

Bowls are inter-changeable as long as you are using an 800 cfm on an 800 cfm throttle plate or 850 cfm bowl on an 850 cfm base. You can not use an 850 cfm bowl on an 800 cfm base; you will loose the idle circuit below about 1,500 rpms!

One major difference is that the 4sp carb used a larger step metering rod to allow(leans carb)the engine to drop in rpms more slowly. And the 4spd carbs used a shorter accelerator cable pin in the throttle arm.


The 6318 used a #1962 metering rod:>>>>6319 used a #1966 metering rod:
economy step>>>>>>>>>>.067">>>>>>>>>.067"
mid step>>>>>>>>>>>>>>.055">>>VS >>>.052"
power step>>>>>>>>>>>>.045">>>>>>>>>.045"

You can use either carb with a 4sp or auto trans and it will work fine after you make simple adjustments such as idle speed, metering rod piston height adjustments and accelerator pump stem height, David.