Hi, I saw that there is a 4.78 ring and pinion set for an MX5, S2000 and FB on sale at eBay and want to know if it’s a meaningful investment.

1. Most importantly, will it fit?
2. Would it invite any mechanical issues?
3. How much would it cost roughly to have it put in (taking the diff out myself vs. the shop do it)?
4. How significant is the acceleration boost versus the stock 4.1?

I won’t be getting it for a while if I get it at all, just would like some input first. Thanks in advance.

 

I myself am interested... especially in #4

 

1. it does fit.
2. not really, although the engine will be revving higher
3. if you pull the 3rd member/pumpkin, which is very easy, a diff shop is pretty cheap to setup the ring and pinion. or some one that was a tech at Ford in the 90's can usually setup a diff too, the Mazda one is easy, and the Ford guys have a lot of experience
4. it depends, but its probably like when you put the exhaust on or something, its pretty big