How hard would it be to run the 360 transmission on a f7p'd 340?

Could you just get an adapter plate made up?

I've looked into this before, it is rather simple if you know what your doing, or have the money to get the stuff made thats needed. This is how i thought about doing it;

First things first, the 340 transmission, 4 mounts on the gearbox, 2 front 2 back, and 4 mounts on the engine, 2 front 2 back/bellhousing. The 360 transmission, 2 mounts on the gearbox, 2 back, and 2 on the engine, 2 front. The 340 gearbox hangs, and the engine sits on its mounts. The 360 gearbox hangs, and the engine hangs on its mounts. Those are the differences

So, put the mounts in the back to hang the 360 box on, the holes are already there just have to put the mounts in.

Make an adaptor to mount the torque tube to the 1.7 bell housing front half (no need for he input/output shaft). You want this for clutch release reasons, and also for the crank position sensor to stay in the same place (360 bell housing doesnt have the mounts for the CPS) The bell housing uses 5 bolts, the torque tube 4 bolts. The torque tube may need shortening as i think the 1.7 bell housing is slightly longer than the 360 bell housing, however its just a big tube so a simple job if you know what your doing. Dont forget to account for the adaptor plate thickness when shortening.

Now the bell housing bolts to the torque tube, and the driveshaft of the torque tube is sitting in the spigot, use a standard 1.7 flywheel, with standard (or uprated if you want) clutch cover, have a centre plate made up to the same diameter of the 1.7/clio but has the correct splines for the 360 transmission. This then means all the clutch mechanism stays the same and because you've used the 1.7 bell housing the crank position sensor stays in the same place.

Now the original 340 engine uses 2 mounts on the back of the bell housing, you don't need these so get rid of them. Then you put the 360 metal 'framework' for the engine mounts onto your chassis rails. I had a look and the position of the 360 mounts, and the position of the 340 mounts is dam close i think there pretty much in the same place. Then you custom make some mounts to go from the block, and from the sump, up to the 360 mounts, so the engine is now hanging in the bay.

That's everything that i could think of while i was looking into doing the conversion, got a complete transmission and everything i was that close. The one thing i have doubts about is whether the 1.7 bell housing is strong enough to take the forces of a solid transmission like the 360's, however i've been informed on here that the 1.7 bell housing is actually a thicker casting than the 360 one, i've looked but i think i'd still have some aluminium reinforcements welded on, simply because im a "just incase" kind of person lol but apart from that, wire it up, plumb it in, all the water hoses should be the same although the engine may sit in a slightly different place, bobs your uncle your away! If some of it doesn't make sense, find some images of the two transmissions and it'll all come together

Hope this helps! Thomas..................

Would the 340 gear lever bracket interfere with the torque tube?

You couldn't put the 360 gearhange on without the front stay bar mounted to the bell housing, although maybe you could include that in the adaptor plate.

Will the 360 drive shaft fit the pinion bearing properly? And will the actual drive shaft be the right length?

Why do you want to change the mountings? Surely more is better, and it doesn't matter if they hang or sit. The early 360s had additional shocks on the engine and diff to absorb the bouncing, these were eliminated later with the glycol engine mounts.

I would go for the 360 diff mounts though, you can't use the front 340 ones and the rear ones might be a bit weak on their own. Good brackets+bushes are hard to come by, you maybe better making your own.

oh yeah indeed there are the few extras but I've just outlined the main ideas I had

i would do away with the 340 linkage stuff completley to be honest, I would indeed add the gearlinkage connection/mount to the adaptor, no point putting on the bell housing as that's yet another 'custom' part eh?

the spigot bearing I presume you could go to a bearing shop for it - 'I need that shaft in that hole, help me out?' haha as for the length to keep the conversion simple I think it would be a case of put the driveshaft in the spigot (out of the car) and then simply work out what needs to be shortened/lengthened to get the bell housing to fit, as you can always add a few inches onto the adaptor plate thickness or even have a new section welded into the torque tube although that adds another 'custom' part to the list.

only reason I went for the hanging on 4 mounts is simply because it uses the stronger available 300 parts and it seeks to work however I'm pretty sure there's a more solid way to go about it I thought the 4 mounts would be sufficient

Thomas.........