[Farmall] H carburetor questions

[kbecker]

Hello Y'all 
I recently started playing with tractors (less than a year). However I have
worked on cars for 30+ years.
I now own 4 H's - and all my cars are gone except my daily driver. My wife
was kind enough to help me here,  she sold 3 cars and a truck in ONE week.
All of the tractors are gas except for the 40 which was originally dual
fuel and this is the one I am working on. (she is GAS only now) 
Here is a link to a few photos. I need to take more.
http://public.fotki.com/772TAS/ih_farmall_tractors/

Basic Kit fits 50981DA OR 45108DB
The Complete Repair Kit fits 50981DA

The dual fuel is the one I have in the shop now and the carb is the last
thing I need to work on before she is ready to go. The question is that the
basic kit says it fits EITHER and the complete kit says gas only.
So what is the REAL difference between the carbs if any? 
The 45108DB is what I have on the tractor (work bench now). The complete
kit is what I have. 
I don't see why the kit won't work. 

One more question about carburetors while I have your attention. 
MY 44 has a 6514DA on which is a 2 inch carb. I am told this came off of an
'M' but I can't find it.
Does anyone know anything about this carb? 

Thanks
Kenneth 



Thanks
Kenneth