Machine tools and stuff...

Lathe or mill?

Ought to have some sort of bar /bushings to line up with the other journals.
Thats what I'm thinkin. A 24mm precision ground reamer blank with a pressed on head, broached to acccept 1/4 hss cutter. Customer left a drive coupler for his line boring machine for me to fit to cutter head. Hope that description makes some cents
 
Just order .125 under bearings for the caps.
Not sure I understand.
Tim are you only boring that fancy cap at the end of the head.........or are you boring the caps at each journal across the head?

What engine is that head fer?
Correct, just matching the cap to the existing cam bores. I do not want to remove any material from the head. The camshaft rides directly on the head with one exception. The exhaust cam front journal(left in pic) has bearing inserts. Interesting, the intake cam has a smaller front journal than the exhaust cam. Both cam front journals are larger than the rest. All other cam journals are the same size(24mm).
Not sure what engine the head is for. The machine shop mentioned "rice burner".
 
Thats what I'm thinkin. A 24mm precision ground reamer blank with a pressed on head, broached to acccept 1/4 hss cutter. Customer left a drive coupler for his line boring machine for me to fit to cutter head. Hope that description makes some cents

Yes, I would still like to see support on both sides of the cut. Typically a bearing honed out to a slip fit. Then use the machine the drive the bars, while being guided by the bushings in the other 2 journals, and the bearing on the outside of the block.
 
Just order .125 under bearings for the caps.

Not sure I understand.

I'm thinking that The Colonel was referring to shell bearing inserts. Order 'em 1/8" loose (which would be .125" over on the cam journal dia vs std) so things have a way of 'self aligning'. Hotdog down a hallway.....