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Differences between carbs from different years

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Old 08-13-17, 12:01 AM
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Differences between carbs from different years

I'm the new owner of a neglected '80 SA and an '84 GS. I noticed that the carbs (and the spare carb that was sitting in the trunk) are slightly different. What changes were made to the carbs during this time?
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Old 08-13-17, 03:25 AM
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Welcome-
I won't even try to answer the question, but it would not surprise me that there is some here who actually can answer correctly.
;D
With evolving emissions, etc thru the models years, in addition to different versions for auto trannys AND CA-spec cars, I think I can safely say there are a L-O-T of differences
that would be a challenge to list. Likewise I am sure numerous parts interchange, since no manufacture wants to scratch-build when they'd rather pull it off the shelf.
As you know, carbs are made up of a LOT of pieces. I am not sure how one would begin to figure out which are similar between years, and those that are different. Arguably one could go thru the parts manuals and look for matching part numbers....
big job tho...

Sorry no clear answer -

Stu Aull
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Old 08-14-17, 08:13 AM
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There are some very important differences between model years of carbs. You can't just mix and match major carb components like the main throttle body and the lower throttle body due to some of these differences. Best advice is to keep the same year carb parts together.

BTW, the SA carb and intake are considered superior to the later FB ones due to flow characteristics.

Jeff20B can fill you in on all the subtle changes over the years. Just search for his threads and start reading if you want an education.
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Old 08-14-17, 12:12 PM
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Um, the SA tops kinda suck actually. And I don't mean that in a good way. They mess up the a/f curve due to limited shrouding of the air bleeds and aren't capable of handling boost nicely like the FB tops can. Thus I've retrofitted FB tops on my SA carbs and they perform better.

The SA intake manifold has better primary runners but worse secondary runners compared to the FB version. The FB version is opposite with crappy primaries but better secondaries. Pick your poison.

A little bit of runner work can be performed on either choice, but you have to be careful. Never port match a manifold to your engine. This kills the anti-reversion lip which you need to keep for these engines to perform at their best.
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Old 08-14-17, 01:34 PM
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Thanks - I'll experiment with these and see what I can do, especially if i end up adding boost
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