squirebill

My Plymouth  Service Manual that covers 1946 to 1954 in the Engine Data and Specifications Chart gives a valve lift of 3/8 inch. for all models P-15 to P-25 engines.   (217.8 cu.in. piston displacement )

Found the culprits!  The upper and lower gaskets on either side of the metal insulator were shifted/misaligned allowing for a vacuum/air leak.  Note that the bore of my insulator is 1.5625 inches= 1-9/16 inches and is correct.  The insulator gaskets that were in my carb rebuild kit were all 1.725 inches.  Too much fiddleing and didleing required to make sure it all aligned with no leaks so made my own with correct 1.5625 inch bore.  All good now.  What was amazing to me was how well it ran at full choke. The leak path for the lower gasket was shaped as a crescent with maybe .050 inch maximum width at the center the tapering off to zero at each end .  It was about a 1 inch long arc. When I compare this  to the flow area of my 1-1/4 inch venturi diameter, doesn't seem to make sense.  Another thing to ponder.     Best regards to all.   

Couldn't wait til tomorrow to check flywheel thickness. Got under the truck with my flashlight and calipers and sure enough it measured 1.103" thick. Guess that solves the problem. Will call Randall at Tennessee Clutch and advise findings and ask if he will make adjustment to raise fingers by 0.200". Let you all know how it works out. Best regards to all. Thanks