Looking at new pitman arms for my 68 and find out they run 145.00$. I've heard that if your running headers (I am) you can use the six cyl. model which runs about 60.00$. Is this true?

Check to be sure that you don't also need the idler and centerlink from a six in order to run the pitman.

When I converted my car to power steering, i wound up ordering a "fast ratio" pitman arm for a camaro, it is about a 1/2 inch longer than standard. I do not think that the camaros had different idler arms. Do a search for David Pozzi's camaro handling web site for more info.

I paid around $55 for the pitman arm at Advance Auto.

More on idler arms, I beleive the 67's are diff from other years. Check this site out:
http://ourworld.compuserve.com/homepages/David_Pozzi/first_gen_suspension.htm