thats my car ^
with a forward facing plenum, and either cross member the stock bonnet will shut.
I used the r33 S1 cross member in the end. it sits a touch higher, but because my car is a drift car I opted for a little higher for more sump protection.
with the a31 cross member, you can use pretty much any mounts with 1 bolt coming out each side, so infact you can go even lower, if you source smaller mounts.
r33 is more difficult as you would have to redrill the cross member, to accept a more common mount.
If you want my A31 x-member, ill sell it for $150. which is how much I paid for it. and I will throw in rb20 mounts and brackets.
pickup sydney northern beaches.
wiring for rb25 in a silvia is a bitch. you have to splice, add, and remove parts from the loom. if u can find a shop that knows what to do... its worth paying to have it done...