Alternator

ok i have 2 crx one is a 89 hf and the other is a 87 si will the one out of the 89 work in the 87 like will it bolt up i know they are the same amp rating an stuff but i want to know if the mount the same

I've never tried this, but I think it will work. The only potential problem will be the round plug on the back of the alternator since the '87 SI uses a 3 pin connector and the '89 uses a 4 pin connector. Other than that, the alternator case and pulley are the same.