A single disc only uses one disc to lockup the converter. the multi disc uses 3 to do the the same job. It really depends on what you want to do with you car. With a multi disc converter you can program the trans to lock with the engines rpms. Plan on paying $750 for the single and $950-1000 for the multi. this is what I can remember. try going to www.tccoa.com then go to tech then tranny. there is info on the converters and the differences.