I’m going to keep the exhaust manifolds but I will be cognizant of exhaust when I mount the crossmember. Attached is the design I’m going with. I’ll bolt it to the lower rail and then use some long bolts and steel pipe like hotrod suggested to bolt to the side rail. I’ve decided not to box the frame. Probably over thought it all but I tend to do that…. This motors been in the truck for 50 years with no crossmember at all.
