Thanks Jon for the ideas. I will pass this along and see what we can determine.
The data I have shows it will work for 1954-61 (respectively) GMC 248 or 270 w replacement zenith number of 11280. I took this info and purchased a 228 NOS from ebay # 11280C.
I put it on as a temp because I was waiting for carbsonly to return the one I purchased from them late last year ( # to be edited).
Take care
