Some late hours on the WWW produced a source for a Zenith.
Searching old shop manuals should that GMC 270 truck engines... including military 4x4 WW II eninge use a Zenith 11275 carb.
Seems a replacement Zenith is still manufactured ...brand new... that will bolt right on the Chev 261 manifold and will even accept the standard 1940 air filter. Basically the NOS is a 28-228 Zenith that has provision for adapting the venturi size requirements to engine c.i. and an adjustable external fuel mixture valve under the main bowl.
The bad news is they are expensive at $625.00 I am told the Zenith will tolerate extreme driving conditions/angle of attack without leaking its precious gas content.
Seriously considering asking Santa for one at Xmas..... or sooner as I have been a very good boy !!!
Comments Jon or other carby officinados !!!!
Stay tuned.
Bob C
Some of what you posted in this post incorrect:
"Searching old shop manuals should that GMC 270 truck engines... including military 4x4 WW II eninge use a Zenith 11275 carb." - NOT TRUE. The 11275 is a universal replacement carb, never original, that may be used to replace SOME original carbs used on SOME 270's.
"Basically the NOS is a 28-228 Zenith that has provision for adapting the venturi size requirements to engine c.i." - AGAIN, NOT TRUE. The 228 series Zeniths come in a variety of internal venturi sizes, but one should not attempt to change the venturi in any given carb, as pressed in airbleeds will be incorrect for the different venturi.
Jon.
