when the timing chain is changed is there any difference in performance and economy?

Thanks

yes it will effect it slightly as more worn it gets the further retarded the cam timing gets, they sometimes slip too when really noisey and will cause the engine to stop running

If you have an spi you can rotate the distributor in it's extension tube right (or is it left?) though to compensate I think?

That doesn't change the cam timing, just the ignition. Except it doesn't change the ignition timing either, IIRC, it's just a distributor for the spark rather than a timing reference.

That doesn't change the cam timing, just the ignition. Except it doesn't change the ignition timing either, IIRC, it's just a distributor for the spark rather than a timing reference.

You're right. The spark is controlled by the ECU so it doesn't matter where the distrubutor is set to as the ECU will compensate and spark earlier/later. I think that's right anyway.

Funny car is the felly. Right on the crossover to fully electronically controlled cars so a bit of a mix of computery stuff and good ol' mechanical stuff!

Phil