NV4500 all the way.
Make sure it has the harmonic damper for the 6.5TD installed or that will cost you some bucks to add.
Now onto your questions....
AFAIK all the old chevy squarebodys had the same motor mounts basically so the 6.2 mounts from an M1008 should bolt up..Again...AFAIK.
I used the flywheel and clutch from a 93 K3500 6.5TD but it came wih my tranny setup. I am not sure about the 6.2 flywheel as I did not try it but when I put them on the counter side by side the 6.5TD clutch/pressure plate looked like it would bolt to a 6.2 flywheel. I chose the 6.5 one because i had it.
The biggest issue is the clutch pedals. You will need pedal setup from 1986+ Hyd clutch truck. Now my truck was an 86 so the dimple outline was on the firewall. I would imagine it would bolt into older trucks but you may have to measure where to cut from scratch for the master.
As far as what slave to use I used an external setup because I had a GM 92-94 NV4500 which is what it uses. I would recommend...Using an NV4500 from a 96+ GM with internal slave. The reason being is that tranny uses the universal bolt pattern so a future Cummins swap is a breeze.
I used the master from an 86,slave from the 93. I had to buy the clutch line for the 93 as the fitting on the slave is unique. Then I cut the line on hte metal part and used a compression to IP IIRC then had a braided line made to mate that to the master. I'll see if I can dig up some pics.
Also the NP208 Transfer case although never factory mounted to an NV4500 does fit. It is the same spline and the bolt pattern is an exact 180 deg mirror.
Hope that helps.
1886 M1008 CUCV
GM4 Turbo,DB24911 turned up.
Raptor 100 lp.
NV4500(the way they should have come)
5 inch Redneckmaster Ex
Autometer Fullsweeps
Serp Belt conversion. HO WP. Dmax Fan
Previuosly owned:
2000 K3500 6.5TD
1993 K3500 6.5TD
1983 K5 6.2
1998 GMC Suburban 2500 6.5TD
1991 GMC Jimmy 6.2
1989 GMC Vandura 2500 Hi Top 6.2
1983 GMC K2500 6.2
1999 Ford Suerduty 350 7.3PS
1983 Ford E-350 6.9
1982 VW Rabbit Diesel