Any problems with putting a GS1000 in a GS850 frame?

[GS850Fan]

I have a second Gs850G (1979) that may not have a good engine and was wondering if there was any major problems with dropping a GS1000 engine I just acquired into .
I could have sworn that I read that the 1000 was the same size engine & trainy that would match all the bolt holes & mounts. However I can't find any info now.
Has anybody ever gone down this path? Is it worth the attempt?
Any surprises that I won't like.

Thanks, Paul

[Steve]

If the 1000 is a chain-drive, forget it.

If it's a shaft-drive, you may have to fabricate a motor mount or two, and you will have to move the entire drive train over, including the drive shaft.

.

[bwringer]

Assuming it's a shaftie, the motor will bolt in -- the mounts are the same. You'll need the driveshaft, carbs, and intake system (airbox & boots) from the donor bike. The throttle is easy -- just eliminate the closing cable.

You'll also need to make arrangements for ignition -- either transplant the electronic ignition from the GS1000 or convert to the points from the '79 GS850. If the 850 already has a Dyna electronic ignition, then use that, of course.

[slaveforthewave]

are the mounts not the same on the chain drive as on the shaft?! they look damn close if not! i just bought a 78 1000 to slap the motor in my 81 850 hardtail frame, and was hoping to run a set of 02 gsx-r wheels and the stock 850 electronic ignition on the 1000.

i hope it is as easy as it sounds!