I would love to help get you squared away with a DIY build kit.
Rebuild Kit:
1) Goerend billet stator, billet cover, triple disk converter in your choice of stall (R, J, and AR options are extra).
2) Full paper/ruber/seal kit (gaskets)
3) Bearings/thrust washers
4) Bushings
6) Hydraulic improvement kits
7) C1, C2, C3, C4 clutches. C5 are included if customer's are hurt, even at 300-400k miles you can typically still read the ink stamping on the friction disks so they are in no need of replacement.
8) Goerned deep pan (can exclude for $200 savings)
9) Goerend C3 oiling PTO cover (can exclude for $75 savings)
10) ATSG manual
These run $3804 to your door plus applicable refudnable core fee ($320 without C3 oil jig, $370 with the jig). This includes a core return label, shipping to you is covered by me (~$150 in shipping to you).