Your doing a great job Mal, if not you who else would be putting in the hard work with this problem?
Well done I say And I'm sure you will get it sorted.

LOL! Install an "O/D" light in your dash!

FAILED FAILED FAILED

The whole plan is fatally flawed
I had not considered the rev/5th selector rod moves backwards into the recess (when in 5th) where I had installed the new switch
Naturally I am very embarrassed and will probably win "Knuckle Head of the Year" award
AAAAGGHHHH

Drilled my 8.5mm hole and tapped the thread, fitted the switch and it works!

Just need to sort out a relay so that the rev light comes on in reverse instead of neutral and all forward gears

update

managed to split my 60A box tonight
successfully drilled a pilot hole and enlarged it to 6mm but now I am stuck because I need a longer 8.5mm bit.
I need the extra length because the chuck of my drill hits the extension housing and stops me from drilling a vertical hole.
Hopefully I can get hold of another drill bit in the next few days.

Looks like there is plenty of aluminium thickness to tap into so this time I wont bother with the metal putty

will do but first I want to try it on my 60A box
cannot see there being any problems but tat could be famous last word-- stay tuned

This mod really needs to go on wiki :)

Congrats, Very creative!

if you have any pic's I'd be quite interested in the end result. I was looking into this a little while back as I was dry fitting my 60A into the coupe so I could make the trans mount adapter & realized what a pain the rev switch was.

when I had the trans apart for rebuilding I thought (cant remember for sure) the end of the rod had a carrier bushing/bearing pressed in the housing so the shaft wouldn't wear the housing. What'd you do to deal with that, drill thru it or whats actually there?

look forward to seeing this as a how to post.
thanks, evan

Good work Mal you five speed god you!

I'll have my gearbox out in the coming weeks will definitely fit one of these. Thanks for the info.

alright no worries i can do that... cheers for the heads up mate