need slant 4 barrel help 170 225

I would think the Dutra Duals would work with the 170. You can go over to http://www.slantsix.org and correspond with Doug Dutra (Dr. Dodge, I think). The 170 is a shorter block than the 198 & 225, so I can see where the headers might not work.

You may want to ask at /6 if all cranks were machined for a pilot bearing. (LA V8s were not). What you will want is a 225 with a crank machined for a pilot bushing. If no swap is feasible, a good local machine shop ought to be able to do the work. They would probably want the crank out of the engine, but what do I know? Good luck.