I’m not a welder. The one on the truck works fine but the flex pipe one probably puts some back pressure in that cylinder as well it’s too close to the steering gear.
Those at 12 Bolt are about 1 1/2 inches too large & they R cast iron.
At this point I think I should take the one I have to a shop & see what they can do with it & start calling around to locate someone that can fabricate one for me.
Then the basic exhaust manifold would work (?) if I can find both the intake & exhaust.