Quote:
Originally Posted by lovehamr
Trans? If you're running a top loader then yes. To do better you'd probably need an OD trans, steeper gears or both. 3.73s are pretty stiff for a car that light with an engine that big.
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[QUOTEEngine is spinning pretty good for a Big Block (unnecessary) try dropping to 3.54/3.50/3.31.
][/quote]
According to any one of the many gear/speed calculators, you should be turning about 2850 rpms in 4th gear @ 60 mph........big cubes,big carb,a lot of rpms, yes that fuel mileage is accurate..........75 mph would put you in the 3550 rpm range on the highway!!!!!!!
By switching to a 5 speed overdrive trans,your rpm drop from 4th to 5th gear will be about 700 to 900 rpms depending on the trans. gearing in 5th gear.......
As stated, the 3.73 rear gear is too much for your set-up, you'd be better off with something in the 3.25 range......
I run a 3.70 rear gear with a toploader in my road race car!!!!!!!
Years and years ago, I helped a buddy drop in a 428 with a toploader and 3.73 gears in his Superformance, I tried to talk him into a 5 speed Tremec,he wouldn't listen,within 3 months he told me he had wished he had taken my advice, he said he couldn't stand to drive it on the hgihway for more than 20 to 30 minutes at a time..........
David
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