Tried google and could not get what I wanted to know how much ingition timing is for slow burn aka bathtub combustion chamber head (287) style compared to fast burn heads (782).

All I know is that bathtub burns slow and need so much timing compared to fastburn combustion chamber which need less timing. But how much?

Reason I ask about this is pervious owner had original bathtub head replaced on this mopar 2.2L with fastburn type but didn't use correct ingition timing curve for it so is there a problem with this? Less performance? etc?
I was thinking of pulling base timing back few degrees to go by till I have
megasquirt installed.

Cheers, Wizard

If it isn't pinging, things can probably wait until you go to a fully adjustable ECU and get it dyno tuned.

_________________
"Mad Scientist" Matt Cramer
'66 Dart - turbocharged 225
My blog - Mad Scientist Matt's Lair