Tony Huttmer of http:www.racehome.com
has had the same problem. He is using the same size tires I think, and the outer tie rod end hits the rim edge.
A short arm clears much better.
As far as I know the long arms are not used on normal PS systems. But my page info is based on observation and speculation. Not any hard and true specifications.
Check my web page for First Gen Camaro suspension info:
David's Motorsports page
First Gen Suspension Page
67 RS 327 Origonal owner. 69 Camaro Vintage Racer, 65 Lola T-70 Chev SB Can-Am Vintage Racer