Hi,
The water pump is about to go on my '85 944, I can get my hands on a newpump for a 924, will it do the job or are they radically different?
Thanks.

 

They are interchangable with a 924S waterpump, but not a 924 waterpump. Also, if you have the old style pump, you may have to update the timing belt idle roller as well (you should replace all the rollers while you are in there anyway).