PACT sells a heavy duty overdrive spring for $70. That and some good OD clutches along with the oiling mods to the shaft should support quite a bit of power?
A friend of mines 440 Duster is running 121 mph through the traps with a 518 with Ultrabell. Full street car with steel wheels and power steering.
Just a matter of time before it grenades. It's a shame Chrysler didn't build a better OD Unit. They were no doubt the weakest OD units of all Makes ever made. I know you can beef them up a bit but they won't take a beating especially behind a big block. Hell you can even make the Ford AOD stronger than the 518.I debated about putting a 200r4 behind my car but I was too proud to GM it. So I'm putting the 833 back in it.
A fellow club member has an original '70 Superbird with 426 Hemi and he runs the Aluminum case 833 with OD 4th gear to cruise to car shows...but he does not race it, of course. He saved the OEM 833 on the shelf so that when it comes time to cash in his "401-K" Superbird he can say it is numbers matching and mean it. Some years ago, he and several other club members drove the car from Everett, WA to Talladega, AL. There was an event to celebrate the NASCAR reunion for all the aero cars including the Phords. Most of the participants trailered their cars, but Bob Kropp (AKA SuperbirdBob) drove his. They were made to be driven, weren't they???
