25S14

Hey, anyone here put a nissan stagea rear subframe into a nissan s14 silvia befor? ive brourt one for my silvia bescause there 25mm wider each side and puting it in i have run into a problem. So it was a tight fit to put subframe in but once in with my locking collars the back to holes bolted up find and the front 2 can bearly get a theaded on and even the left hand side front theres a gap of about 30mm between top of subframe mount and chasis. Unsure if i need special mounts? Any help much appreciated