Me and my coworker did a 6 speed into is300 a while back. There's some fab involved in the shift linkage and driveshaft. It's really not that bad definitely doable.
It's just that damned tranny is very expensive.
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Part of:
Wangan Midnight Maximum Tune 2 sedan expert.
APXRO: JZX100 Chaser "Odaiba Romance" 815HP/DG B1 2 overhauls. secret weapon
PM!: UCF10 Celsior "Jealousy" 810HP/DG B3 0 overhauls. vs battle car