I had a set of KYB Gas-A-Just´s (the white ones) on a 68 Mustang I had earlier. I thought they gave a too harsh ride in that car, so I took them off and replaced them with softer shocks (Monroes I think).
After purchasing my Firebird, I wanted to replace the front shocks. I found a set of white KYB Gas-A-Just´s at a swap meet that looked like they hadn´t been used much, so I bought them and put them on my car. To my surprise, they give a firm, but not harsh, ride in the Firebird. I like them a lot.
Maybe the KYB´s match the front-heavy Firebird better than the light Mustang (with a 289), or maybe the shocks has a lot of more miles on them than the unworn exterior finish give apperance of???
I would be afraid that the regular, silver colored, KYB´s would be too soft, but I hope you get more point of views before you make a decision.