russ d
+1y
get 4 lug nuts from a 80's model chevy truck, the closed type, slather some jb weld inside them and they will screw right onto the exhaust manifold. Adds a bit of chrome too! I cant take credit for this tip though, my crazy Mazda friend Crutch did this to mine when he dropped the motor in for me. I was like "holy shit thats awesome".
For the lower tubes, take a jig saw with a metal blade and cut some 3/16 plate to match where the tubes bolt on. Drill matching bolt holes, slather it with JB weld, and bolt it on.