NA8 5 speed into a NA6

[GAGE]

Hi guys,

Just purchased an '89 MX5 (actually a Eunos roadster) thats got a Greddy turbo kit, coilovers etc and it happens to have a shagged input shaft bearing in the gearbox.

It looks like it might be cheaper/easier to buy another gearbox and I was thinking about installing a later model 5 speed out of a '97 NAB. My questions are:

a) are these boxes stronger/superior to NA6 gearboxes?
b) will my flywheel/clutch/shifter/tailshaft all fit up?
c) will it throw out my speedo?

Any help with this would be greatly appreciated, many thanks to the seller who "forgot" to mention it

[CapitalF]

Hi

Ive just done a similar swap a few weeks ago and the answers are:

a) I was told that the newer box has some stronger bearings internally - but gearing etc is all same. They are nearly identical g'boxes.
b) "unplug /plug in" - for me at least
c) not likely - but I think there is a different coloured gears (look in the end of the speedo cable when you undo it) available that Mazda fitted to match up with changes of diff ratios over that period. Could easily be wrong on this. I re-used the cable /gearing in my original unit so no problem at all. You can do same.

Cheers
Peter

NB All the above is based on the smallest amount of experience, swapping my g'box over on my own recently. I'm no tech guru. Others on here can add more...