"J" Cylinder Block same once there isHi-vo chain?

Once the cylinder block has the Hi-vo chain guide set up, are they basically the same besides 1000 or 1100? I see quite a few for sale but a lot of times there is not a year on the adds, just pictures. Or is there some difference in the guides/ tensioner on the early Hi-vo setup, vrs the later "J" series?
Also what about 17mm vrs 19mm wrist pins, when was the change?
Thanks for the help.

Have you read this from Ape Race Parts?
www.aperaceparts.com/tech/techkz1000.html

I have now, thanks again.

Another good article about transmission undercutting:
www.aperaceparts.com/transmissions.html

Those folks must be pretty sharp :laugh:

I am still wondering if the newer block from the police bikes may have some differences. On Kaw.com it shows the old "J" block supersedes. Would there be some up grade to this newer version? Possibly cast with a different fin design for better cooling, is what I was looking for. Maybe they upgraded the casting? Just a curiosity as when there is a supersession, there is a change, usually for the better design.

The 2005 1000P engine is identical to the 1981J in all aspects excluding carburetor setup, cams, and 530 chain. They even went back to the old stile ignition with the mechanical advance and old stile pickup coils and IC igniter.