2556015 is 27 inches tall.
2356015 is 26.1 inches tall
You will be lowering your final drive.
Your final drive of 3.55 will make it feel like a guestimate of 3.68 or more.
Quicker off the line,but highway RPM's will increase slightly by 50-100RPM's.
Hope this helps.

Last edited by 68Cbarge; 01/16/18 06:04 PM.
'68 Newport Custom Barge on a Budget!! BOAB
1973 Satellite WAGON! 318- 3 on the tree!!
2008 Chrysler 300c HEMI!