The Stovebolt Site Forums The Shop Area Engine Shop '61 235 carb question

Hi all. I have a '61 235 motor ready to put in my '53 Chev 3/4-ton. If you all recall, I pulled the old 235 out and had to replace it because of freeze damage. The newer 235 didn't come with a carb and I want to use my old one which is a Carter YF 1-bbl, 2100S. I noticed recently elsewhere that a 2100S is supposed to be for a '47-'57 Chev 235. So the question is, will this carb work on a '61 235? I am assuming my intake and exhaust manifolds from the older motor will align and work on the '61, so I can't see any reason why the carb shouldn't work. Any ideas? I want to keep the old carb if possible. The '61 235 was from a car. Thanks!

The carb should work ok on 61 engine. As far as I know manifolds are the same. I always thought that original carbs were Rochester model B?

Yes, that's what I thought, too. Not sure what the story is on the Carter YF, but I was surprised to find out the 2100S is specific for '47-'57 Chev trucks, or thereabouts. Maybe the Rochester was on a 216 for those early model years. I always thought someone had changed the carb on my old 235, although that motor was a '55 and, therefore, not original to my '53 truck. Anyway, thanks for the info. I thought it would work, but just wanted to double-check before I invest further in the old one or buy another of the same model.

Rick,

Not that I'm alone on a mountain top with flowing robe and long white beard...

All 235 carbs are "interchangeable"; the lineage is supposedly thus:
Chevy sixes-1932-49: Carter W-1
1949-67: Rochester B (& variants)

The Carter YF (as I understand it) was an aftermarket replacement carb.

The thing to watch out for is this: the Rochester B had two different size throttle-bodies (the cast-iron base), the smaller one for the 216, and the larger one for the 235 & 261. The jet sizes are different for each engine too.(if you're shopping @swap meets)

In short, if you pulled that YF off a 235, it'll fit your new 235.
At some point, GM stopped using the thick carb insulator spacer under the carb, so your '62 studs may be shorter than the ones on the '53 engine.

Thanks Frank. I'm using the intake and exhaust manifold from my old 235 for the '61, so the studs are the same as before. I'm looking at a replacement YF carb that is the same number and is for a 235 Chev, so this should work as well. What you said about the YF being a replacement carb makes sense. The shop manual shows it should be a Rochester as well, if memory serves me correctly. Thanks again.

Frank54,
Why did they use the spacer under carb? Was it to insulate from heat? My '53 uses spacer under carb. I have a Holley Pro Injection 1 barrel, it's for a jeep 258/ Chevy 250/292. It uses a heated waterbase under it. Chevy 250 don't have spacer so should I leave spacer off 235? :confused:

Whitelightning;

You've got a Holley 1 BBL Projection? Where did you get it?

Dude :p

Whitelightnin',

Not sure why the insulator is there, but it goes back to the first downdraft carbs in 1932.
Probably to prevent percolation and vapor lock.

I'd say that if your vehicle came so-equipped, leave it that way.

I think it also has to do with the heavier trucks that used a governor in place of the spacer; that way the manifolds are made with one legnth of stud: no governor- use spacer; governor- no spacer, same studs.

My 250s w/ Rochester "B"s don't use the insulator.

Other ideas?