What was the last year for the slant?

I want to build a cast crank turbo someday for the Duster. It is much lighter, anf can be cut down to be even lighter. Get-er-spinnin quick! I have plenty of forged stuff.

If you want to spin find a 170 and add boost. I am curious how a 170 would rev with a set of light modern rods and pistons.