Cad 500+

[SRB]

Hello to all

      New to the site but not to the qjet!  I've had good experiences with these carbs on other GM engines but not the Cad yet.  All my currently aquired 1969-75 engines currently have the stock qjets.
     I keep reading about 800cfm and 850cfm models.  Some articles say 1977 and newer  Cad 425's are the "big" qjet but also say watch out for the lean smog carbs?  Is it all 1977 and newer big blocks? I'm beginning to think they (of this year and newer) are all the same base casting with some minor internal changes.
     I want to start with the largest and most adjustable/compatible qjet  for a cad 500+, 10.25/1cr, some port/valve work, warmed over nicely on pump gas. Trying to maintain sane fuel mileage.  Just your basic want it all deal...

[Cliff Ruggles]

1975 and later will be the larger castings.  Even though they are all equal from a performance standpoint, I'd avoid the 1975 and eary 1976 models with the aneroid located APT system.  The 1977 and later units will have the APT in front of the power piston, but are otherwise about the same as the earlier 75-76 units.....Cliff