Hey guys, i have a JDM b18c gsr (black valve cover) engine and box. I am currently trying to LSD the gear box with an aftermarket Qualife differential. My problem starts here:

When i opened the gearbox i realised that the differential had been replaced already seeing as there were pieces of metal broken off from the inside of the bell housing. All the gears and countershafts are in excellent condition, there is no signs of wear. (I presume that the japs changed all the internals)

After removing the differential that came in the gearbox i realised that the japs used a B16 differential so the ring gear had a different internal diameter than the one required for the GSR LSD i bought. (I measured with a Vernier to verify)

I know that the b16 ring gear has a ID of 109.8mm and the GSR ring gear has a ID of 116.8mm.

My question is, would it be ok to get a machine shop to mill the internal diameter from 109.8mm to 116.8mm or is this not acceptable?

(reason being new final drives are rather expensive and my car is NA)

Thanks alot for any assistance you guys can render!

 

Unfortunately, opening up the center bore is not the only modification that would be required. The bolt holes are drilled too close to center as well. One would have to re-drill all ring gear bolt holes to match the larger differential. If the final drive ratio is 4.40, one could easily source a genuine 4.40 ring gear and simply bolt it on. PM me if you need one... I believe I have one.