coppertopgmc

I have a 1970 Oldsmobile Toronado that I think has a switch pitch converter. My cam manufacture calls for more stall than stock, but my trans shop can not tell me if it can be done to my converter, or can I put a non-switch pitch converter on my trans TH425

joe_padavano

Switch pitch was not available in a 1970 Toro. Unless the trans has been modified (it is possible to retrofit the S/P pump and converter), it's a single stall speed converter. Does the plug on the side of the the trans have one wire or two?

coppertopgmc

I have read that switch pitch converters were only used until 1967, but my 70 Toronado does have the two wire connector also my 70 parts car also has the two wire connector, My car is the GT the parts car is not. I can't see that both cars would have been modified, I don't know if only the toronado continued to use the switch pitch converters?

joe_padavano

In the early 70s, the second wire was used for the Transmission Controlled Spark, part of the emissions controls. You should have a thermal vacuum switch someplace that controls the vac advance. The second terminal is connected to a pressure switch inside the trans that signals the vac switch to allow vac advance in top gear.

coppertopgmc

Thanks for the info. that really clears alot of things up for me. now I can just have my converter guy build me a stall converter, anyone have any suggestions, my cam says 1800 rpm, but my car is heavy do I need more stall or any other modification to the converter