Hangn69
09-16-2020, 05:54 PM
ok my 1969 catalina wagon has the standard 2.whatever rear differential which is good on fuel but nothing else. Does anyone know what year differentials/axles will be a direct swap?Is it 67 -70? Are there any differences between the those years stated?I want to go with a posi with higher gearing if possible.
north
09-18-2020, 01:50 PM
The standard ratio for Catalina wagons in 69 was 2.73 for the 400 2bbl and 3.08 for the 428. And because of the very tall tire sizes on these cars the 2.73 equated to a 2.56 on a GTO sized tire and the 3.08 equates to 2.78, so definitely highway oriented gearing.
Unfortunately the 65-70 Pontiac fullsize car differential is a unique beast with basically no interchange outside these years and models.
Anything with a greater than 3.08 numerical ratio are hen's teeth and finding Safe-T-Track units are also very rare. The 3.42 (which equates to a GTO 3.23) is a sweet setup but hard to find as it was only typically used on those rare 421-428 HO cars.