Besides getting away from nitrous you might not need to do a lot of de-tuning. The gearing and stall converter are all that are keeping it from being streetable. The TH-400 is a fairly low geared 3 speed auto. Couple that with the 3:73 rear diff and it's winding up pretty good at highway speed. There are some good GM 4 speed autos that would let you keep the 3:73 and drop the RPMs at highway speed. Having the extra gear and dropping the stall would make it more driveable yet still aggressive.
Bowtie Overdrives
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