I just replaced the 4 speed trans on my 77 280z with the trans from an 81 zx. The clutch seems to be slipping pretty bad. We replaced the clutch with a 77 clutch kit. I assumed this trans switch was a simple switch out but apparently its not. Do I need to change my slave for a zx slave? Do I use a bearing/collar from a zx? I have adjusted the pedal in, out and to spec without a change in slippage. What is the correct combo of parts to do this correctly. By the way the clutch was just a regular replacement from the auto store, nothing special.

You use the bearing collar that came with the transmission (they might be the same length). Did make sure you put the clutch plate on the correct side (flywheel side is different than the pressure plate side)?

I was directed to this site to show the different collar sizes.

http://www.zparts.com/zptech/articles/trans_swap%20parts/4tobear_specs1.html

does anyone know if my 77 4speed collar is different from the 81 zx collar? I dont know how the clutch inners work but I assume a different size one isnt letting the plates come together all the way. Do I need a different fork or slave from the zx?

In my searching i have found that I probably have a mismatched part. I have read that the clutch on back should match the trans. That means I may have the 77 collar, bearing, fork and slave which should be 81zx parts. Is this correct or can I keep some of the 77 parts?

The B type forks are the same. The key difference in all this is the length of the bearing collar. The clutch plate and pressure plate is the same (as long as you are not switching between a coupe and 2+2). You can keep everything except use the bearing collar that came with the transmission you are installing.

I am using the collar that came with the 5 speed transmission. I assume the clutch may not be to spec so the type b 5 speed collar is too short. The collar that was in the original 77 4 speed type b is probably taller(according to zcarparts.com). That collar would match my flywheel. I guess that is the only other type b collar.