Cheers for info guys.
I guess I should have been a bit more specific.
Its a fairly old 307 hooked to a powerglide.
I guess it would have originally come out of one of our
69 or so HK Monaro's. [old Aussie muscle.lol]
The main graduations "before" after 0 are 4,8,12,16.
At idle of about 1100 [I dont have a tacho silly me] I have it at
8.Like i said it seems ok but not sure if its optimum.
Kind regards
Shane.