Yes, but you'll need to change the input shaft, input shaft cover and bellhousing. These boxes normally need rebuild/overhaul anyway so just do it and change the bits over. It'll probably need a cluster and 1st gear plus synchros too.

You'll need a V8 M20 input shaft too. And make sure you get the right cover for it (V8 3spd are the same and so are V8 M21). The only thing to be wary of is there are 2 x types of front seal. Early ones (much of HQ) have a scroll seal, from later HQ to WB they had a neoprene seal. The covers are different for the 3 x types of seal, so make sure you get a later type of input shaft cover as any repro input shaft you buy today will be the neoprene seal style. These guys sell the input shafts, but there are many otehrs like Kingswood Country in Victoria:

https://www.americanauto...form=product&option=925

http://stores.ebay.com.a...7&_trksid=p4634.c0.m322

Make sure you get new needle rollers for the input shaft to main shaft bearing, and get a new input shaft bearing as well. I'm pretty sure you can change the input shaft on an M20 without disturbing the rest of the box if you are careful, just getting the new one to slide in with needle rollers intact and aligning the synchro ring up can be tricky. One of the boxes (M20, M21 or M22), can't remember which is much harder to do this change with the cluster gear in place as 4th gear (on the end of the input shaft) is bigger (I think it is the M21).

If it is a HT-mid HZ bellhousing assuming yours is a HQ. Mid HZ-WB have a pull type (full cable) clutch which won't work with your HQ. You'll also haveto chase down a V8 bracket for the HQ clutch rat-trap mechanism. It is the bracket that bolts to the bellhousing. The rest of the clutch rat-trap is the same between V8 and 6cyl.

You'll be able to use the input shaft cover off the V8 3spd too, as long as it is later HQ onwards.

Thanks guys.

I will keep your number handy dirty dave.

I will get it started next week.