Holley model #, and backfiring thru carb

["Myron Ware" <cmw@domain.elided>]

Hello all,
  I'm trying to locate a carb rebuild kit for the 1-bbl carb on my 
'70 196 motor.  I know it's a #1940 IH model carb (side-hung float 
bowl), but my NAPA guy couldn't find a suitable cross-reference 
number for a kit in his books.  I couldn't find the Holley model 
number on it (it's supposed to start with an 'R', that's what I'm 
told).  Does anyone know of a current part number for the kit, 
and/or the Holley part number for this carb?
  I'll ask another question while I've got your attention:  The 
engine will backfire through the carb occasionally when taking off 
from a stop, and sometimes when I punch it while already moving.  
I've got a Pertronix module in it, and it behaves the same way with 
the vacuum advance disconnected and plugged.  Are there any obvious 
items I can check for while awaiting my rebuild kit?  It worked fine 
over the summer, and then it just started acting up one day.  I need 
to get a timing light to make sure the timing's still there, but it 
runs fine at idle and revs fine with no load applied.
Thanks,
Myron
------------------------------------------------------------------------
C. Myron Ware   Senior Prog/Analyst, CNE |  NASA Langley Research Center
Email c.m.ware@domain.elided             |  Hampton, Va   23681
http://cnb-www.larc.nasa.gov/~ware/cmw-home.html  (work) or
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I would kill everyone in this room for a drop of sweet beer. 
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