LDB C5

I am thinking about swapping my MN6 for an RPM MN12. Is this a direct swap? Are the input shaft splines the same? What, if anything else will I need to change?

TIA

BlackZ06

The only difference between the gearboxes is the ratios ....

Tranny specs:
Coupe ------ Z06
2.66 -------2.97
1.78 ------- 2.07
1.30 ------- 1.43
1.00 ------- 1.00
.74 --------- .84
.5 ---------- .56

Note 4th gear is the same in both boxes.

Also, the RPO codes are ......

Coupe and Convertible is MM6
Z06 tranny is M12

RPO MN6 is a "manual transmission provisioning" code ... all 3 cars with a manual transmission have MN6 .... if you have a Coupe you have both MN6 and MM6 codes on your build sheet ... if you have a Z06 you have MN6 and M12 on your build sheet.

LDB C5

Are the input / output shafts the same spline?

AU N EGL

YES.

There might be some slightly used MN12 boxes out there. Lots of Z06 guys are taking out the MN12 and putting the MN6 for the gear ratio.

FrankTank

Len, let's chat about this over the weekend. Also, give Rodney at RPM Transmissions a call about this..I was considering doing this when I upgraded my MN6 Trans to their Level IV, and Rodney advised against it..not because of part compatibility or anything like that..more with the ratios and other stuff, andhow the ratios effect 1/4 driving etc..
Just a thought

93Polo

I did the swap because I ran across a great deal on a M12 built by Rodney. IMO I liked the M6 better.

Independent1

As the other posters have noted they are completely interchangeable. Having driven both MN6 and M12 vettes, I prefer the M6 ratios for street driving. Requires a lot less shifting especially around town.