I had a 1971 Monte Carlo with a mild 350 TH350 12 Bolt . I would do these 3000 to 4000 RPM Neutral Drops Man that car would burn them tires 100' FT . Well one day that TH350 said no more and went to Lunch My Brother thoght it was funny . He said his OLDs Cutlass TH400 was un-breakable . Well in a way he was right but his driveshaft was not Its alway a lot of fun till you break something