Essentially what it does is be shorter than the stock piston and allows an additional clutch plate(and may be a steel not sure). It is the same thing the 2004r builder does when they cut .080 off the od piston and slip an additional clutch into the overdrive.
There is actually a factory 6 clutch piston/drum combination.. but yes, often times it's easier to simply machine the piston, vs searching for Hen's teeth.
I bought what Bruce said was on Ebay $ 30.00 I guess it is for (6) clutches. Jim told me he's using Raybestos green clutches. I'm gonna buy them next week. the company I bought the (billet) clutch plate (conversion) they have the clutches too. But they were $250.00. gonna purchase them later. I don't want to take his tranny out again if I don't have to. That's why I'm asking you guys for advice so I get it right 1st time.
My 77 Delta has a 70 Cad trans with the 6 clutches, seen now and then. i noted they just made the piston thinner. I bought one too, but haven't had a chance to rebuild another trans with it yet. Yes needs another steel. I don't know how others set the stackup clearance. i have a couple boxes of steels sorted by the thickness, which varies a lot. A little mix & match will give the right total. Bruce Roe
Wow...I'm a bit surprised by this. I know Olds W30 OW trans had the 6 disc setup. I had thought the Stage 1 trans would have had these, too. 'Course Olds did pioneer the auto trans.......
Steve, Raybestos Hi-energy (green) in the direct clutch only.. I use the Raybestos waffle pattern HD clutches in the forward and intermediate. JW
Some good info here for sure. Not trying to hi-jack but have a question. What do the guru's here think of Alto Red Eagle clutches and steels? I already have them to install in my 65 ST400, so I'm going to use them. Was just curious of what people think on these. I have heard of the Raybestos clutches recommended here, but never used the personally. Also remember to have the trans guy swap out the brass balls for Torlon Balls(that's just fun to say, Torlon Balls). The shift kit from Transgo may already have them, I haven't looked at the kit yet.
I'm using asset of powerglide Red Alto clutches and Kolene steels in my ST300, like them a lot but after one season the shift seems to have gotten softer. Still shifts well though.
my trans has the red clutches with extras and kevlar bands heavy duty sprag and manual valve body. shifts great!
Hey Jim hoping you can help me out. I bought the 6 disc piston. When I asked the guy for Hi-energy green he said he had them . But also said he only had 3 green in forward. and said other 3 rear would be steel. or viceversa. Did not want to be forced to buy something! What's the deal? can you give me specific part#'s Bruce ! this piston came in Delco parts sealed bag. interesting.