has anyone put 89-91 rear struts in an 88, i know the 88 has a forked strut, and imformation would bevery helpful.

 

You need to swap to 89+ lower control arm (or whatever it's called that the shock bolts to at the bottom).

 

89-91 rear shocks have a fork on the end, the 88's have a bushing that the LCA surrounds on both sides.
Struts are on the front of a 1984-1987 CRX they not only support the weight of the car but also are carrying side loads and thus have a larger diameter shaft to take all the extra abuse compared to a shock that sees most of its forces just straight up and down.
88 LCA bent/rolled sheet steel
89-91 LCA solid cast