bobss396, 1900 rpm @75 mph with my Tremec 5 speed in fifth gear is what my 63 Belair does on the highway. First gear still low enough to light up the tires. Definitely not doggy around town. Gary
My '57 Chevy PU has a 3.08 rear, L60-15 tires (about 30 inches tall as I recall?), the 454 is an LS5 from a '70 Vette, factory rated at 390 hp, 525? I think ft/lbs of torque, other than some head work, intake/carb/exhaust, it's pretty much as GM made the engine. Only track time was once in Sacramento on a hot, muggy summer night, and turned 14.02...felt like I was running through mud that night...I know it has 13's in it, but since I don't have a slip for it, didn't happen...anyways, a decent 454 with tall gears will pull, anyone who doesn't think so has never had one with tall gears. Oh, yes, TH400 from the same car. PS... Re: the overdrive increase of MPG vs. payback vs. cost...it'snot all about when you'll break even, or get ahead. It's about keeping the beast under the hood happy, and not letting it scream it's lungs out if you're heading down the highway.
Had a 502/502 BB in my '70 Chevelle w/TH400. Gear Vendor Overdrive, 3.31, 245/45X17s & barely getting 200 miles out of a tank of gas on the interstate. Solved it with this!! WARNING!! Not H.A.M.B. friendly!!
Thanks for the info, I think the 2.75-3.00 is on target. My last post stated my rear axial code which is KC G201 1 1. I have not been able to find that KC code's ratio so I am still shooting blanks. Thanks much
Shows how much I know about a Tremec! If the 1st gear is low enough that's a different story. Take the 1st gear x the rear and mine comes up as 9.95, which is a good ratio for take off. Anything over 9 is pretty good.
My motor home had a 4.11 gear with a 454 and turbo 400 . I towed my race car trailer 75-80 mph all the time and didn't have any problems except burning a few plug wires once in a while. No tach, but those dual 3 inch pipes with flowmasters sure sounded good coming out in front of the back tires. People would turn and look when I came into the pits until realized it was my tow vehicle.
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