Luftman.One of the MVVS carbs I used (I do not remember if it was in the 40 or not) was a few
thousandths off ( to big to plugin) I took the carb apart and chucked it (the body) venturi up in my drill
press and filed it smaller (no lathe) till it fit, installed with the O ring of course and tightened the screws to lock it. It transitions better idles great very much like my irvines and as I said
before run pressure. One of the carbs was too small in diameter so I did a wrap with shim
brass and used copper kote the red stuff for a good seal , Did not want to use JB weld so
I could remove it, So if too big or too small thats the adaption. I have used OS 10 size carb
on the smaller paw s doing this. I know some of you have mini-mats or some other sort
of lathes/milling combos so it would come out a little neater.