billlopez

I just purchased a 1978 with a 350. Going thru and checking everything out I see the previous owner put a performer RPM manifold and a qjet #17058229 which I looked up as a 1978 400cid truck carb. It has #64 jets and 39B primary rods, DR secondary rods and G hanger. Everything seems to work on this carb, including the a/c idle speed kickup and the choke. Am I loosing mileage by using a carb without the APT? Being a 350, I assume its jetted wrong since its off a 400. Any recommendations?

speedreed8

https://www.corvetteforum.com/forums...quadrajet.html

COOLTED

Congrats on your purchase. I believe that all qjets have APT. Follow the advise in the post linked to above, and worry about mileage later.

Sigforty

All the carbs after 75 have the APT just depends on the style. Most of the truck carbs have the APT screw in the baseplate under the fuel inlet. It probably has a plug in the hole to prevent tampering you would have to remove.

You should check out Cliffs high performance forum. They are a great stop for qjet tuning advice.