95 blazer 4.3 4x4 transmission shifts hard into 3rd gear and wont shift into overdrive. What all transmissions inter change with this transmission to swap out

Did you ever find out what ones will interchange

a lot of times it's just for and debris in the transmission even just a piece of blind can stop a transmission from shifting pick up a bottle of seafoam trans tune... it's for hydraulic systems automatic trannys and power steering systems it's a pint cost about $5 dump that rate in and it will dissolve all the gummed up things.. works wonders for me I swear by it