81 xj650 looking at swapping internals need info

Ok I have been tearing my engine apart to clean and rebuild and I am wanting to beef up the power in it also. I have been reading and if aI understand right I can put the 750 crank/rods/pistons in an it will give alittle more. Also though I read I could swap out the 900 top end as well. Finally we are able to swap cams out in these engines as well.

So my question is which would give me more power and a broader power band.

750 crank/rods/pistons and head with 900 cams in it.
OR
900 complete top end swap
OR
750 crank/rods/pistons with 650 head and 750 cam

Will these work and any info on performance of the combinations is appreciated.

Cam swap info on chacal 's parts list its about 3/4 the way down on page 2

 

I'm interested in this as well.

 

Ok havin' some trouble getting these parts off. Mainly it is the gear set on the right of the screen and also the gears that the thick chain is around and am needing help with removing them.

Also this is the how it looks in my mind now I just gotta put it together the same way.

 

I was thinking of something a little similar but different as well. i was going to bore a 650 out 1mm and top it off with 750 cams but not sure on what head, 650 or 750. Also gonna be running pods and a very free flowing 4 into 2 exhaust.

 

Hey wondering if anyone had a diagram of how to build an engine stand for this motor or if I am on my own figuring it out and answers to any other questions on here would be nice. thanks

 

Ok I'm planning on going with this combination
750 crank/rods/pistons with 650 head and 750 cam
Would it be better to bore out the cylinders I have or to switch to a 750's set of cylinders? Also would I have to get work on my head to accomidate the 750 pistons or would it be fine with out any?

Also does porting help on these bikes cause was thinkin of getting it done when I got head rebuilt. I am planning on running a free flowing exhaust on it with K&N filters so I know I will have to rejett the carbs but with the head rebuilt and ported would it be major this is just so I know what to expect when doing it.

Info is greatly appreciated fixing to start buying parts and I also have parts to seel in for sale section that I am not going to be using.

 

Hey I have a question. My bike desn't have the yics on it so is that gonna matter when I swap camshafts or is it ok?????