If I want to install a spring/strut combo without decompressing my current set, all I need is an extra pair of upper strut mounts, right?

Do I have to buy OEM or are there aftermarket pillowball mounts I could buy?

 

not sure about the compatibility of pillow mounts from other manufacturers and your springs.

therefore, i would do it safe and get the factory upper mounts.
but you may need to compress the front strut a tad to get clearance
unless you're going to take apart the lower control arms. i didn't want
to take anything more apart than i needed so just compressed the
strut a little bit while it was on the car for ease of removal. then
compressed it off the car further to undo the mounts.

you can even rent a spring compressor at autozone or buy one for like
$20. imo, don't waste your money, just use the factory ones you got.

 

I considered doing this as well. Then while I was at the dealer for service, I walked over to the parts department and found out the mounts were $62.50 *each*. So for $125, you could do it. I decided not to.

 

Thx for the responses guys.... ended up reusing the stock mounts. I think Performance Nissan (mynismo.com) wanted $45 each for the mounts but then you also need the other stuff... boot, bumpstop, etc... plus the rear mount plates as well. Just got to be way too expensive!