2000 Posts and climbing!!!
Join Date: Apr 2016
Re: MFWD Front Axle Pics
Yeah, bolting it straight to the gearbox housing would make for a pretty short wheelbase.
Either they would have a frame that goes in between these two parts, and the engine sits on top of it, or, they made for the engine to "be" the frame between these two parts (like older tractors I've seen).
You probably don't want to do "use the engine as part of the frame" with the Cummins you have coming in, and since you can't find the frame rails in the parts you have, I think it's probably fabbing time. You could start with making plates that will bolt to the the gearbox and the front wheel mounts, then I would suggest waiting until you get the engine, so you can fab this frame from the gearbox forwards (so the engine crankshaft is aligned with the transmission input shaft and is the right distance from it for whatever clutch you wind up using), and clears the engine going forwards so you can still work on parts of the engine without having to remove it (ie maintenance and repairs), and then position the front piece so when the front wheels are mounted the tractor is about level.
See, it's simple.
Edit: you may also want to go back to the specs for the tractor you bought, to see what wheelbase it says the tractor has, so you can make it at least that long for stability...