727 Rebuild recommendations

While my 1969 A108 van is being repainted and I'm waiting on engine parts, I have the stock 727 tranny sitting in my garage. It was parked for 14 years prior to me buying it. What are people's recommendations for it? Supposedly it ran before it was parked but everything is caked in dirt. Do I:
A) Put it back into the van once the engine is back (building a 390 stroker from the 318 case and probably adding a 2,000 - 2,5000 stall torque converter) and then deal with any problems as they arise?
or
B) Rebuild it now while I'm waiting for the other parts to be shipped and assembled?

If I decide to rebuild it, what kit should I go for? I see ATP Automotive kits for $91 to TCI kits for $290. I have a FSM for my van. What other information do I need? Special tools? Lastly, the rear tail for these vans is slightly different than most- are there any special seals in them I need to be aware of?

Thanks!
Joe

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