Ih exhaust manifold spasers for 426

Probably was me. I made them for my D-21 that I had some 30 years ago. With a Bosch "A" pump I was able to spin an Air Research TO-8 turbo.  I made them out of 1 inch thick steel blocks. The holes that attached to the 426 cylinder head were countersunk and used short 1/2" NC Allen head bolts. The DT-400 series manifold bolt holes were top and bottom so the blocks were thick enough to be threaded and hold the IH manifold up against them. It was very time consuming to make, as the IH manifold is only two pieces, instead of three like the A-C manifold. So you fudge a little bit on how you make the spacers. The A-C ports are rectangle while the IH are square, so you spend a lot of time with a die grinder blending the spacers to fit each port. It was all worth it, but will try your patience getting it done.