I spotted a mistake:

Higher numerical rear axel gear ratios (called lower gears for some wierd reason) are better for lower rpms and lower speeds.

Lower numerical rear axel gear rations (called Higher gears, for some strange reason) are good for higher RPM engines, higher speeds and fuel economy, which is why they are called 'highway gears'.

For example... 2.06:1 might be great behind a 572 CID V-8 that can turn 8,000 rpms no problem and is looking to do 150 mph, but ain't gonna work so good with an inline 6 that max's out around 4,000 RPMS and is only marginally safe stability and handling wise at 75-80 MPH.

Conversely, if you want to go 75-80 on the freeway 7:06:1 gears won't work too well for you unless you've got an absurdly numerically low 5th gear ratio, like .3:1.


'51 Chevy 1/2 ton w/'62 261, HEI, offy, fentons, dual carter/webbers, t-5 & 12 bolt posi