I have had friends with Chevy's and Fords that ran those spec converters, 3800 and similiar plus or minus........and they all had 4.10's as me, similiar power and or a touch more at least off their dyno sheets but I had a custom 8" 52-5400 range one done and I ran high 6.60's and low 6.70' and they were all low to mid 7's in the 1/8th.........piss poor useless converter pick is what i'm hanging my hat on.