I just did a partial tune up on our '86 345. I installed a set of Taylor Extreme Duty wires. WOW are they great! 10mm wire, nomex fire boots on plug end. Fantastic. They are on the pricy side ($180) but they should last a very long time.
Speaking of a long time, one of the things I replaced was the coil. The one I took out had a build date of 2/19/85. That would make it the original coil with 157000 miles!
And all I noticed was a very slight stumble pulling away from a stop.