54 Chevy 2 door post rear gear.

[Ziegelsteinfaust]

I am slamming my 54 210 post back into a modern safer daily driver.

1979 Buick 231 V6, slightly ported heads, gasket matched heads/Edelbrock intake, hei with weight kit, th200r4, and a Isky mile a mor cam. The rear tires are 245/45r17. Or 25.5 inch installed height roughly. Daily curb wieght with me ,and my son in it should be just under 4000 pounds.

Cam specs.

Valve Lift Int/Ext. 0.425/0.425
Valve Lash Hot Int/Ext. 0.000
ADV Duration Int/Ext. 248/248
0.050 Duration Int/Ext. 194/194
Lobe Center 108

So which gear ratios would you Vote for.
Cruising rpm defined as 75 mph to keep up with traffic easily.
3.89 gears with a 2589 cruising rpm.
3.73 gears with a 2470 cruising rpm
3.55 gears with 2351 cruising rpm


I am leaning to the 3.91's for better street manners. As that would be most of it real day to day. I currently rarely hit the freeway except to go on a trip litterly. Plus the factory straight 6 used 4.11's with its overdrive trans, and slightly taller tires.