Ring and Pinion question

Any body know if this is the right ring and pinion for my 61 with a 7.5 stock rear.

Ford 7.5" (3.45 Ratio)
$142.95
F7.5-345
RATIO: 3.45
MANUFACTURER: Motive Gear
MATERIAL: 8620 Heat Treated Alloy
CASE BREAKS: NONE

Never mind I found out I have a 7" rear and I am just going to have to swap to a 9".