A great diff conversion for V8 & VQ swap cars

[40flash]

I have just installed the ultimate semi-affordable Diff for a VQ or V8 conversion (in my opinion). It turned out to be much easier than I expected.
The gears that work for street driving with a turbo four are too low (high numerically) for a V8 or the VQ.
I am in the middle of an S14 VQ swap. My goal for the diff was two fold.
I wanted the 3.538 gear ratio that is found in the stock 350z diff. I also wanted a Helical diff. Here is how I achieved the goal.
I started with the pumpkin out of a 1996 Infiniti Q45 I had removed at a U-pullit yard for 65 bucks. . If you'd rather have the 3.7 ratio then start with the 97-01 Q45 which comes with the 3.7. The reason I started with the Q46 instead of the Z dizz is because the Q45 diff bolts into the S-13/14 subframe and the Z diff doesn't.
Next step was to buy an S15 helical diff off Ebay. Be sure you get the output shafts with it. You will need them and it's usually cheaper that way.
Since the Q45 diff comes with the same 3.538 ring & pinion as the 350Z I didn't have to remove the pinion gear at all which made the helical install very easy. Simply remove the output shafts (I used a rubber hammer) unbolt the old diff from the Q45 pumpkin, remove the ring gear from it and bolt it onto the helical diff with the ring gear bolts from the Q45. (Use thread locker).
Bolt the helical assemby with Q45 ring gear into the pumpkin being careful to put all the shims back in the same way they came out. Check the back lash to make sure it's within spec. With mine I had just a tiny bit too much slop (backlash). I made a new shim out of a beer can and put it in on the left side to get the ring gear just a few thousands closer to the pinion. The pinion height won't change from the factory setting since you don't have to remove it from the pumkin. I checked mine just in case and it was fine. Tap in the output shafts, fill with oil and put it in the car.
Side benefit is that the Q45 diff comes with a speed sensor that can be useful to make your speedo work because the VQ trans doesn't have a speedo sensor like the stock trans did.
When doing an engine and trans swap you will need a new driveshaft. I would recomend Doing the rear end swap before making the driveshaft as the Q45 diff is about a 1/2 inch longer than the S13/14 diff because of the speed sensor. The Q45 also has a larger input flange it uses a larger input flange. I left the larger flange on mine since I have have a new driveshaft done anyway but I believe you can swap flanges if you want to use the stock flange.
This is a much easier swap than fabricating a 350Z into a 240sx and you end up with a helical diff instead of a Viscous diff with the same gear ratio. Hope this helps someone. John