Stock Crank Question

[seabeenugent]

Is it safe to assume that a 3.8L stock crank that has a 5/8 harmonic balancer bolt is not a “turbo crank”? No rolled fillet.

 

[seabeenugent]

Can anyone help me with this? From what i have found online the harmonic balancer bolt changed from a 5/8 bolt to a 3/4 half way through 1977. As far as I know there were no turbo 3.8L before 1982 or so.

 

[bison]

Can anyone help me with this? From what i have found online the harmonic balancer bolt changed from a 5/8 bolt to a 3/4 half way through 1977. As far as I know there were no turbo 3.8L before 1982 or so.

Im not sure about the date they changed but i ran a 5/8 bolt crank out of an even fire 78 Turbo regal with rolled radius on the rods for 6 years and now whitettype has that exact crank in his engine. That crank should be in the hall of fame since it has laid down some excellent numbers and has not failed. Turbo 3.8 was available in late August 77 for the 78 model year.