Boxerworks.com

for the taste of this Biscuit............... I would do this

Use the /5 to /7 motor......... pick the power
Use the /5 to /7 frame as the motors will fit all frames
Use a later R65 sub frame for the non wire through the frame for a stronger subframe
early SWB drive as I beleave they were strong enough

any /5 4 speed OR later 1975 to 1980 5 speed tranny

or later R65 for stronger materal.
A Earls fork
13" Harley Sportster shocks

Big tank
flat seat
full fenders

Use a /5 wire system for full needs and sase
Kick or electric start.
my bike is similer to this plan........... its great but the Earls and bigger big tank I don't have I'm useing a early /7 tank

The output flange of the /2 gearbox has a different bolt patern than a /5. You will need an adaptor flange to mate the two. The adaptor flange will make a SWB shaft too long for SWB swingarm. The flange would need to be almost 2 inchs thick to use a SWB shaft with a LWB s/arm, and that would be a week spot.

The /2 motor/trans is slightly longer than a /5 when measured from output flange to motor mounts.

A /6 driveshaft fits a /2 rear drive, swingarm and frame with a /5 engine and trans.

I would try a /2 driveshaft with a LWB swingarm, then check how much overlap there is at the rear drive splines, you need at least 50% mateing and no binding through the arc of travel.

Garnet, thanks for this. I came to the same conclusion. I have bought a cheapo /2 driveshaft on eBay to test with. I'll let you know how it goes. One thing if have not been able to determine is whether a /5 output flange fits on a /2 gearbox. I know the output shafts have the same taper. Is it possible it fits? This could be the simplest solution to overcome the bolt pattern differences without using a spacer and causing length issues....

Thanks again