Re: Correct carb for 63 Wildcat with a 425
The 1958-69 Buick parts master catalog shows it to be a Carter AFB 3578A; - there is no listing for the Rochester 4GC for the 425. The funny thing is the listing is for a 1962, 1963 is the only year that isn't listed, so I'm assuming it'll be the same as 1962. In 1964 they used a different transmission, so the throttle linkage is going to be slightly different.
So there's a very good chance that it's an AFB; - that said, anything from 1961-1963 will probably physically fit as long as it came off a nailhead engine. Then it's just a matter of jetting and tuning. As stated, the 64 and later had a different switch-pitch linkage that is not on the 63 edition, which had a stator control instead.
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