I had to trade a set of aluminum roller rockers for a set of stamped steel/roller tips.. the valve covers wouldn't clear the rockers.. and I couldn't use taller valve covers and get the accessories ( A/c, etc) to fit. the stamped steel ones worked fine for 50K miles+ the extra lift seemed to help at higher rpms ( this was a 85 bonneville- 5.0 4bbl). as long as you have piston/valve clearance and valve covers height isn't an issue I'd do the real roller rockers. but, the stamped steel/ roller tips are fine. the name brands will insure that you REALLLY have 1.6 ratio. Stock parts tend to vary even at 1.5. If you know that you have dished or falt top pistons, you'll likey be fine on clearance... but it pays to check// ESPECIALLY if you change cams!!