Tried to find bolts, 8mm x 150mm, to replace trans bolts in order to slide the trans back from clutch housing
to keep everything aligned.

No luck.

Went to Brafasco here in Ontario, they specialize in fasteners.
Didn't have the bolts that long but they did have 8mm threaded rod.
Picked up a 1000mm length of 8mm threaded rod for $5.19 + tax.

cut to required length and go...

Is there any video or pictures of this technique and do you need to remove exhaust to do it?  thanks

Yes, you'll need to remove the exhaust.  Not sure if that answer is 100% but I always do.  Makes it easy to get the wheel off and the exhaust is out of the way.  On a K100 you're best off removing the headers and exhaust can as one unit.  If you disconnect the headers from the exhaust then it's a PITA to get things lined up properly.

I've found it easiest to get the transmission fairly well lined up within an inch or so of the bellhousing and then install two or three long hex head M8 bolts.  I had a set with the heads cut off and screwdriver slots cut in them but the hex head approach works better for me.

The Exhaust can remain in place.

There is a series of 6 vids on youtube showing spline lube HERE

martyman wrote:Is there any video or pictures of this technique and do you need to remove exhaust to do it?  thanks

I always find Chris Harris informative and entertaining. Try this https://www.youtube.com/watch?v=HZJdZ1HszkA

klamityboy wrote:

martyman wrote:Is there any video or pictures of this technique and do you need to remove exhaust to do it?  thanks

I always find Chris Harris informative and entertaining. Try this https://www.youtube.com/watch?v=HZJdZ1HszkA

I'm a fan of Chris and in his vid he removes the exhaust...I'd rather not if I don't have to...

You don't have to.
I've replaced clutch without taking exhaust off, you may just want to take the weight off the exhaust to prevent any strain on the headers whilst you work.