SRL Diff in a SPL

[Datzoom]

Yes, it will bolt in to the roadster housing. The 3.5 is from a different Nissan application that runs an H190 differential.

[twinight]

I run 185/60/14 Before i had 175s?? I would get more speed on the freeway but take off would tremble a bit. Now the car takes off faster with the smaller tires.. and still manages to 3,500 rpms at about 75mph??.

I have the same size tires and the car runs 8mph slower than what the speedo says. I use to run 4400 rpm @ 80 mph, now with the 185's I'm at 4800. The car will redline at going 92 or so whereas I could reach 100 with the 175's.
I was thinking of going to a 3.7 to compensate, but I think it may be less expensive to change tires.
Check your speed w/ a GPS. Your speedo may not be off at all.

[67 1/2 1600]

You are right. I may not be off at all... When it says im doing 80 im passing traffic.... which is amazing for a +35 year old car.