[GMCNUT]

Originally Posted by Funky61

I was not aware that there were 305A's with a two barrel. I thought the 305D was just the upgrade to the two barrel and all else was the same.

Anyway I found this in the Archives so maybe Lewis will chime in.

from the Archives by Lewis Matkin.

"LEWIS ELLIS MATKIN JR" wrote: > > These are the differences with the 305 engines. > 305A: 1bbl carburation 1904 series Holley, series 1000-3000 1960-61
> 305B: 1bbl carburation Zenith-Stromburg, series 3500-4000 1960-61
> both of these are gross 150 hp engines. > 305C: 2 bbl carburation WW Stromburg, series 3500-6500 1960-1974
> 305D: 2 bbl carburation WW Stromburg, series 1000-3000 1961-63
> both of these are gross 170 hp engines. All of the engines above are 4
ring piston engines. > 305E: 2bbl carburation WW Stromburg, series 1000-2500 1963-69
> this engine is 170 hp gross, and is equipped with 3 ring pistons.

I bought what appeared to be an untouched 61 GMC K1000 suburban and it had the A motor with 2bbl. Was a late 61 truck based on production number so thinking somewhere mid-year the A's might have got upfitted. Don't know