Re: 1969 power head to 1989
Physically, the 69 block will fit. The problem is the ignition. If you are intending to use the original distributor ignition, there is no problem. However, the ignition switch needs to be rewired. Two "M" terminals are not used and blue wire connects to "I". White wire is tach signal.
I suspect that you will be dissatisfied with the performance of the '69 block though. Even though it is rated at 85, it is not going to put out that much horsepower. Old school--small ports--three rings instead of two--two caged needle bearings in each piston (more resistance)--block may not be "packed" for better volumetric efficiency--less efficient inter-cylinder seals on crankshaft. The 85 was probably a theroretical paper figure based on mathematical formula calculations of bore, stroke, RPM, and compression. You will also want to change the head--newer heads cool better.
If you want to use the newer Force ignition, you will need to modify the top of the block to receive the alternator carrier. That involves drilling (5) 1/4 X 20 holes and adding a spacer to retain and locate the top crankshaft ball bearing. You also need to be certain that the seal is properly located in the carrier and on the crankshaft because the old block is about 1/16 to 1/8 inch higher here. There is no change needed for the newer tower though.
If the block is apart and in pieces, you can enlarge and square the ports. This will gain significant horsepower--enough to make it deliver a true 85 at the prop. If you want to see an example of porting, go to The Chrysler Crew, join, go to photos, go to Frank's boats.
