I suppose your tractor is fitted with the Euro 1/Tier 1 engine, 3.9 liter. Older 4341 could have the 3.6 engine. ??
Anyways, the 3.9 liter puts out 75 hp in the 6341, and 84 in the 7341, with turbo.
On the older 2 series, the exhaust manifold including pipe, were different because the turbo bolts straight on to the manifold, on the front end of the manifold instead of at the rear end of the manifold.
Plus, you need to install an
oil cooler inbetween the spin-on oil filter and the original mounting place (take off filter, mount oil cooler, re-mount oil cooler on top) including some plumbing of hoses to the oil cooler, and oil lines to and from the engine, to supply the turbo.
The engine will last at 85 hp. The transmission is exactly the same to the 85 hp models, though the gear ratios are a wee bit lower in the 4341
the main differences between turbo 84 hp 7341 and your 4341 are the gear ratios and the tires. (and off course, the turbo/oil cooler)
I have no idea about the exhaust valves, though the 7745 turbo uses a different cylinder head.
I think, you shouldn't bother about the cylinder heads (lower
compression to equal up for the turbo) or the water pump, working in snow at frosty temperatures will give you plenty of refrigeration capacity.
The exhaust valves, i will check that for you.