I am working on my '51 GMC with a '54 chevy 235. It was a driver and had to park because the acceleration got really horrible/restrained like it was choking. Many comments from peanut gallery lead me to replace carb and distrib and install electronic ignition kit to eliminate points & condensor.

Fuel supply from pump seems adequate so other forums tell me its the acceleration pump on the carb and not the thermostatic coil on the manifold which I found not operating.

SO I got a rebuild for my "old" carb which is the Carter YF2100S. It seems in good shape and I found a scanned rebuild manual on the oldcarmanualproject.com website. But I am noticing two discrepencies from the manual (for a'49) that may be non-issues.

So I ask this forum if anyone knows if this carb changed design such that there would be NO accelerator pump intake screen. mine doesnt have one but instead there is a small steel ball trapped by a brass retainer. My new kit has two diff steel balls. SHOULD I PRY OUT THAT RETAINER? If I damage it, I doubt I can find another.

Second question: There is a brass jet that appeared on my workbench during disassembly. I think it is the accelerator pump check and was supposed to have a retaining ring (that was missing and so it was held in place by the gasket). ANYONE KNOW IF THIS NEEDS/HAD A RETAINING RING? My rebuild kit has a small "G" shapped retaining ring so maybe this is it?

Thanks for your advice and expertise...My last possible explanation of my root problem is that I may need to do a valve adjustment because I am doubting this is a carb issue....

1951 GMC with positive ground. Engine is a ‘54 Chevy passenger car (Serial Number 0024472F54Z) with a ‘56 head (casting code on top of head 3836848 GM 4), Casting Code (on passenger side on side of head B56 848 850)