68 Camaro Widest front wheels on a standard subframe?

[MR BIG]

Hi guys how's things? I'm new to this site and hopeing you can all help me out with this problem i'm having with my 68 camaro..

I'm about to start a build on a 68 that I imported last year, I'd love to run either a 19" or 20" front wheel that needs to be a minimum width of 8 inches wide. I'll be looking to stay with a standard subframe as the shipping of one to Australia would cost me a packet, what's the widest rim/tire combo I can run on the front? Also if any of you guys have some pics of a 67-69 with 19" fronts and 20" rears it would be helpfull.. Thanks