.....Do you want to race it or "run" it .....I have "donated" EW643
block and cyls to someone for a Thunderjet ....You can cut the air
duct and recoil stuff off and remount a diff recoil system to the crankshaft
and you will have trouble finding proper free air heads ..The ignition
will just be points and it will be a "fudged" machine ...The output end
of the crank is probably wrong as well .....Long and short....
You could build a runner but not a racer from the EW....
Better to find a GP643 since it has a CVT pulley already and do the
other changes ....
If you already have a chassis ,,,can it be made a "SR433" instead ???
Stuff a GPX motor in it ???
RON