My old 76 D100 went from knocking on the 9.99 door to 9.96 after the swap to a s60 , both rears had 4.88s don't remember what the weight difference was I don't think it was much the 8 3/4 had a back brace.
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1963 Thunderbolt 496FE 10.80 (still a work in progress)
1968 Mustang slow a$$ 428 FE
1971 Boss 351 Mustang 11.20@115mph
1993 Lightning 10.61 @ 129mph 408Ci A3 headed NA
1996 Viper GTS
2001 Lightning 8.99 @ 155MPH 5.4 Mod Motor
2009 Ram 9.65@144MPH 463CI G3 NA
2010 Challenger 9.91 @ 139MPH 408CI G3ci NA
2019 F150 (local dealer's Lightning package) ..11.90s
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