I did consider a T5 conversion for my 1985 Ole Yellar Astro van project.Those van's wt are near or over 4,000 lbs.The 85's did come stock with a 4.3 T5 and although somewhat rare to find,they are out there.Well I talked it over with a tranny shop that I have known for yrs and trust.Toni the owner of the shop told me that tranny is one of the weakest trannies GM ever built.I asked him what about the WC ones.So Toni waked me back to the shop and showed me a 55 gallon drum filled with WC and NWC broken parts that he had fixed.

I am apart of a Astro forum too and there awhile ago we had a member go threw to build the ultra T5.He changed out to many of the WC parts and aftermarket heavy duty parts because he has a 383 in the van.Trust me he had big$$$$$$$$$$$ money into that.