Hi Guys, I'm trying to get my 1963 D470 running, came into compression problems. Low compression 60 lbs. I have installed NOS cylinder,piston and rings(3). Also new case gaskets and crank seals along with a new reed and carb gaskets.I have rebuilt carb with needle valve and seat, float and gasket. New coil, points and condenser. Ring end gaps are .015 staggered and on solid material in cylinder not on any ports. Still seems to me not enough compression to start, 60 lbs. A few times I did have luck and it started but most times it won't start. My cylinder prep was light hone clean up wall, end gaps are .015. There is no needle bearings on crank shaft just brass bushings and seems to be no play at crank, new seals are installed. Anything I might be overlooking ?