Author Topic: '75 and '76 cadillac quadrajets  (Read 1016 times)

Offline v8440

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'75 and '76 cadillac quadrajets
« on: October 06, 2022, 07:19:43 AM »
Hi all, 
 
     I've heard before that '76 cadillac quadrajets are particularly desirable for some reason.  I've also read that the '75 and '76 cadillac quadrajets are the same.  I don't see how this could be true, as according to Cliff's book, at a minimum the apt setup would have been different between the two years.  Are either of those carburetors particularly good for some reason?

Offline Cliff Ruggles

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Re: '75 and '76 cadillac quadrajets
« Reply #1 on: October 10, 2022, 11:09:53 PM »
In 1975 the first of the early APT models showed up.  The APT system is just horrible and located in the front left corner of the carburetor (as viewed from the front).  Some of these early APT models also had an auxiliary power piston assembly and single jet/rod, another not so good feature. 

They carried some of them over into 1976 so when you are shopping for Q-jet cores look for the plug over the APT system to be located in the CENTER of the airhorn and partially covered by the air cleaner gasket.

For several reasons the other APT models aren't that great and for good reason Rochester very quickly quit making them and went to the later variety instead.....

Offline v8440

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Re: '75 and '76 cadillac quadrajets
« Reply #2 on: October 11, 2022, 04:51:30 AM »
Well I don't know where I got the idea they were particularly good, maybe what I heard was they're valuable to people wanting the correct carburetor for their '75 or '76 cadillac and I scrambled it in my own mind.  Anyway, thanks for the clarification.