TECH: 1948 Panhead FL Cylinders

I don't really notice the difference.  One cylinder has a -48 part number.  The guys that know will point to fins and a weird, little boss.  One thing for sure, these were pitted from "bad storage."  The gasket surface was very rough and pitted.  MFM (McFarland Machine I call him) . . . indicated, and utilized a live-center cone and turned these cylinders -.010 off the head gasket, and -.007 off the base to clean 'em up.  I had to check the fire-ring flange vs. the cylinder head chamber depth -  to verify depth to compress the head gasket fully . .  and we do - all ok . . . Now we have equal lengths and flat, true surfaces for our head and base gaskets.