Ignition timing, Jeep 4.0
So in my crappy Hanes manual (provides mostly common sense instructions) and elsewhere they say that the ignition timing is not adjustable on my '96. I've always thought that a different vaccum diaphragm could be installed to enable a quicker advance and all... right now it's bone stock with a previous-owner-had-it-installed smaller than stock exhaust.
Compression ratios on these things run 8.5 to 1 so I figure there's some room to bump it up for more power (and possibly economy?). Or would I have to swap in a distributor for an older AMC six to get adjustable ignition timing?