Hi ya,

I would rather have say 7 degrees and the shim if needed, 8.4 just sounds tomuch, over kill?

Yes that sounds reasonable I also got an old skool tester who said " mm rear wheel drive I will give it some throttle, that will help" and off he went
The problem with iva is that it says int book of rules "must show a degree of self centering " now if that isn't open to individual testers interpretation then I don't know what is
Good luck