Eric Fuher

I just picked up a 66 cadillac calais that has the sp400 in it. Was a project car from the previous owner. I dont have a convertor for it as he tossed the old one and the ls i am putting in requires a 3200 stall. Can a person just put an aftermarket stall in these with no issues or should i scrap the idea and go with a non pitch trans? Searched on the form and found a lot of info about the trans, but did not come across this question. Thank you for your time

oldcutlass

You will need a SP converter. They are still available, Fatsco is one source.

Eric Fuher

Thank you sir

matt69olds

The switch pitch trans is a pretty neat setup. Supposedly Hydromatic stopped production because some customers didn’t like the whirring sound the trans made in the high stall mode, and because it was more expensive to manufacture.

There are still companies that can build the converters. The switch pitch has a following with the Buick crowd. I know Kenne Belle offers custom converters. From what I understand the switch pitch stator becomes a weak link around 600-650 hp.

You can convert the switch pitch to a standard 400 by swapping the pump and input shafts. Don’t scrap the switch pitch stuff, people are looking for those parts.

66luvr

All true.
Plus the s/p converter from a 2 speed transmission from a 65 - 67 "A" body Buick or Olds will go right in the 400 and work just fine and adds a good bit more stall, high stall that is. The blue car pictured in my posts has just that setup behind a 455 Olds.
Jim Weise owns this forum and can educate you in all things abut these transmissions, and get you a converter,

http://www.v8buick.com/index.php?for...rformance.100/

joe_padavano

Well, the BOP trans doesn't bolt to the LS without an adapter, and even the Jetaway converter isn't going to get you 3200 stall. SP converters with custom stall speeds are pretty hard to come by. Of course, actual stall speed is a function of the engine torque also - an engine with more torque will stall a given converter at a higher RPM than will an engine with less torque.

Eric Fuher

Thank you everyone. Going to end up changing the trans setup. Going with a standard bell 400 and having a coan convertor built. Seems like the best way to go for my situation right now.