missing a conclusion i see now.
according to my tuners there is a reasonable differens in vlave timing between the 2 marks, but how that will effect they couldn't say.
they didn't recommend 4e marks on my 5e
i need to take a look on the position difference to give my final conclusion.
as my car has a standalone ECU, i think i can (if i switched) role out the ignition difference.
I've just tried this , I have a 5efte with a power fc and timing set on 4E mark , while keeping the ecu programmed to 10deg on idle in a 5x5 section of the map.using a timing light the distributer read 10deg on idle.
now I timed it to the 5E mark, the exhaust (and intake) cam needed to be
advanced for the 5E marks to line up with the crankshaft mark at TDC .
now advancing the cams will retard the distributer , or so i found with my 5x5 idle map still set to 10 deg when i checked the distributer ignition timing i found it to be aprox 8 deg , thereby i assume that changing the marks from 4E to 5E will advance cams 2 degrees and retard ignition 2 degrees.
just tried out the car on 5E marks , it picks up faster , less turbo lag , a lot of mid range and some what diminished top end compared to when it was on 4E, i think i just have to test this on the dyno .
btw SPUDDY what became of your test?