Match Race = 1968 Road Runner '383' vs. 1964 Belvedere '426-S' Street Wedge

The 906 heads flow better, better cam and intake, better avs carb, better complete exhaust, better hurst shifter on the after February RR, didn't the early 8.75 rears use more power to turn? My 4 gear RR came through with the hemi leafs!