Will the exhaust from a 75 MX400 fit properly on a 75 DT400?

I can’t say with 100% certainty, but I doubt it, a couple of obvious differences is the 1975 MX exits on the right side of the bike and the 1975 DT exits on the left hand side of the bike. They are also different on how they exit on the cylinder on the engine, and the heads fins are recessed in different locations.

Ha. Ok, but other than that, would it fit?
I'm joking.
That being said, here is the 400MX pipe I was questioning, in case anyone is interested. (Not mine)
Seemed like a fair price.

I’ll let you know in a few days. Just pulled my dad’s old 400c outta storage. It has a leaking head gasket due to a helicoiled head stud that failed. After reading the Super DT thread, I decided to go with the YZ/IT cylinder/head combo.
I highly doubt it’ll clear with the stock head as the fins are probably too tall. Oil tank will have to go.
The pipe in that ad you posted is missing the head pipe.