Changing transmission from 10 speed to 13 speed

Hey everyone. Thanks for the info in the previous post about the Detroit 12.7, good advice.

This truck has the Eaton Fuller 10 speed, would like to switch to 13 speed at some point; hopefully in a few months. Any idea of a ballpark figure on cost on this? Thinking of getting a 13 speed core that I could exchange with Microblue for one of their rebuilt transmissions. I know I have to get the driveshaft shortened. Any other issues to look for in this process. The truck has somewhere in the ball park of 1.1 million miles, at least that is what the engine ECM is reading; have no way of knowing if the engine has been changed or not. The speedo has been replaced so I can't go by that; thinking if may have more miles; so anyway the transmission is kind of sloppy in shifting so it seems to have some wear.

Would also like to put in a clutch with an EZ push pedal of some sort, the one that is in there is a killer; never run across one so hard to push in.

In recap need advice on switching to 13 speed on a 1999 T600 with a 10 speed currently, 12.7 Detroit. 3.55 rears. Thanks. By the way I did get into this truck fairly cheap so I have a little to work with; in case you're wondering.

 

FRO15210CP. It's a 1550 foot pound transmission, which makes me wonder why the clutch is so heavy. Wouldn't think it would be that heavy of a clutch in front of that transmission. Kind of wondering if there is something wrong with the clutch or it's out of adjustment in some way. I have it at my local repair shop right now and they are going to look at it; but haven't gotten to it yet. They just finished the notorious Detroit diamond seal oil leak on Friday; so may get to that on Monday.

 

Driving a 579 Pete with the 13 speed so that's got me a little spoiled; the clutch is like pushing in the clutch on a Honda Civic or something. But my previous truck was a 2006 T600 with the ISX and the RTO16913; don't remember the clutch on that being anywhere near this hard either. Could be that I'm a little soft as I'm been out of trucking for a couple years!