225 swap

My memory is lacking today but seem to remember there was a change in the 225s in 1976. I don't remember what it was. So my question is I have a running 76 dart I bought to swap the 225 into my 68d100. Was there anything that stops the swap. I was thinking I might swap the head , intake, etc if needed. Also the truck is manual and dart is automatic. Can you use a Dakota bushing (or another if different) to accomplish the swap?

I haven't messed with slants much. Everything else has a v8