4.56 gear with the 31/18.5-15" tires (they grow to 32" tall at speed), Billet 2004R, turns just 2300 RPM on the highway at 70 MPH with the converter locked. It’s about the same as a 27” tall tire with a 3.73. Just looking at ordering some new slicks for this summer.
Ordered these today, less width, lighter, good reviews, will be mounted on the 14” wide wheel. For the street I will use these, 31x16.5-15 on the spare rims.
If you do not plan to have that car on the rd this summer I would not get them yet. The moment you buy them the age of the tire starts, you do not want them sitting around getting old.