help on transmission

Hi,I am a 65 year old Florida gearhead and I have been working on my hot rod since 1991.It is an 86 Vet with a 400 sbc bored 40 over with a LOT of performance part's.The car still has the T.P.I. fuel injection.My question is about the transmission.Like all stick shift Vet. guy's of those year's[84-88] I am cursed with the 4=3 transmission.I investigated putting in the exellent T-56 six speed,but was told I would have to change the clutch[Centerforce dual friction],and my custom flywheel.It seemed much more sensible to me to go with the Richmond 5 speed. Unfortunately they are a little to expensive for us[my wife is 100%into this hot rod too].Today I noticed 6 speed Borg Warner transmissions on E-Bay with $250 bid's on them.They are out of 95 LS1 Camaro's or Firebird's.So my question's.Are they different from the T-56?All the T-56's go for $1400 or so.Borg Warner 6 speed's I think I can get for $500 or so.Will they fit?I have the 26 spline input shaft.Will I still need to change the flywheel and clutch?Even if I do I can afford it with the Bourg Waner price's.I hope I have stated the problem in an understandabel manner.I appreciate any help.Happy Rodding,see you at Bradenting Speedway. Don