Boxer Pinging

Just ran my 83 Boxer thru CA Smog and passed! HC were at max limits, but they were during previous Smog check as well.

After check went for a drive on 126 toward Ventura and picked up some serious pinging at 5-6K RPM. I've had this before and changed plugs and gaps and that seemed to reduce the problem.

Before I start spending big bucks, what are the best plugs (temp and type) and gaps? Can't get the Champions the workshop manual recommends, and they seem a little cold anyway.

Thanx,
Mutt

 

Agree with your sentiment that (while we all wish we actually needed the stock "cold" spark plug) going 1 heat range hotter isn't an unreasonable thing to try/use (at least in the US). But if your problem is detonation, going hotter (from a stock equivalent) doesn't seem the right direction.
What spark plug is in the car now? (i.e., Did someone already step up a boatload in heat range to address a HC/oil fouling problem?)
By the NGK numbers, you'd run BR8EIX (perhaps sans resistive extenders if so equipped) at .020" gap (so that would be BR7EIX up 1 heat range -- http://www.clubplug.net/retail_iridium_ngk.html). The .020" gap seems smallish, but (thankfully) no Dinoplex experience for me .
It wouldn't be a sin to try a fresh set of plugs (especially if you're running the older, large-diameter electrode standard plugs), but if the problem persists I think you'd need to verify the ignition timing is behaving OK as a next step (i.e., OKish at idle and 5000 RPM and changing smoothly with RPM) -- JMOs.