Re: Chrysler 75 / 85
If they are both between 1979 1/2 and 1982, then everything is interchangeable. But don't try to change carbs and expect to get 85 HP. you will still only get about 75HP, maybe a tad more, but nothing to write home about.
Even after 1982, Force ignition components are completely interchangeable as long as the ignition system is wired the same. That is, quick connects or terminal board wiring.
Basically, before 1979 1/2 Chrysler had a 2 piece lower unit and for the most part used Motorola ignition components. These are not interchangeable with later units without changing the complete ignition and modifying the alternator mount/crank upper seal.
The basic block was unchanged from early '60s to the time Force was discontinued. Minor changes were made to the head and ignition systems and flywheels were changed and the later engines had a bigger bore but other than that, take whatever you want off the 85 and put it on the 75. If you are handy with a drill, you can even retrofit the earlier engines with the later Prestolite ignition systems; you only need to drill and tap (5) 1/4 inch holes for the alternator stator carrier/top crankshaft seal and fabricate a spacer to hold the top bearing down.
