Camshaft

I having my 1981 kz1100 top ended rebuilt. Going to have the engine ported and polish. wante keep the stock pistons in but, put a mild camshaft. My mechanic said you can just do a cam but need to see if they have one that has less them 260 duration and .50 of lift. I been looking but haven't had any luck finding them. would love to find some mv29 smoothbore carbs. but hard to come by at a decent price. any help is gladly appericate.

Depending what model your 1100 it is you might be able to go for hotter factory cams; 1100R GPz11 1000J etc ?

You need to do a bit of research about valve lift and piston valve pockets if mixing and matching.

Alternatively a base circle skim of your installed cams would increase the lift a touch but (nearly) keep the duration?

Getting a good cylinder head job would be my priority here.

Here's something interesting I've learned. If you buy an aftermarket camshaft for a J or Gpz. it's actually a KZ camshaft casting and does not fit correctly in a J/Gpz head. I know, I know. They've been selling them and running them for years.

1 - The 3 bolt adjustable sprockets are offset with the crank. The chain is off to the left side and wears the top-outer edges of the guides.
2 - The cam lobes are off center with the buckets on 3 of 4 cylinders.
3 - If you have a J with a manual tach, the drive gear on the cam isn't even close to the driven gear hole in the head.

All the cam manufactures do the same thing.