well something some have done is take the secondary butterfly out of a Qjet carb bore the 1bl carb out cut done the buterfly some How much I have no idea. And install it in the 1bl carb. JAck somers is one man who has been doing this type of mods for some time now.. about the only other thing I can come up with is make sure You have the carb For the 292 Then make the mods to That one.
Running a 194 head On a 292 with a true flat top piston can Net Compression Better then 12-1 Hope this helps }[oooooo]