Yes I used the stock rb20 mounts. I had to slot the holes in the s30 cradle a little foward (about 1/4 inch). This swap is easy. And it runs like a beast. I have a rb25 turbo, 440 injectors and NIStune to tune the ecu. I think I'm going to put a holset hx35 on it to see how that runs.
Wow! Happy I found this! I have been searching through the forums all morning trying to decide which mounts to use. I read a couple people saying that they weren't sure if the rb mounts could be used but I'm extremely happy you cleared this all up! I just pulled the engine out of my 280z and I'm putting together my list as to what parts I need to purchase for the rb20det swap and this saves me a lot of trouble and money . Thanks again Pat! Also if you're still making those rear sump oil pans I will definitely be contacting you to purchase one within the next month or so! All the aftermarket ones I have seen go for crazy money.