Rearend numbers on 1968 Charger R/T

[4402tuff4u]

Since my body guy is now starting on the undercarriage of the Charger and had it on the lift to install the rail connectors and prep work. I went to pick up the gas tank he removed because the fire marshall does not allow him to store tanks in his shop. I snuck underneath to look at the rearend and I'm wondering if someone can help me decipher what these numbers mean on the rear end on my 68? one little steel tag was inscribed with the gears 3.23. The other little tag had what I believe was "7 x 3" (?) below the large number on the housing. I know that my R/T did not come with the suregrip option. I'm not ready to convert it to a clutch type suregrip at this point - too many things going on at this time, but I'm doing some research on it so when I'm ready, I know what to get. Can this non-suregrip rear end be converted to sure grip just with a unbolting and bolting up new assembly? Simple as that, or does it have to be shimmed, adjusted and precision work done to it? Thanks for your help.

[John_Kunkel]

The housing pictured is commonly referred to as the "742" (last three digits of casting number), it has the 1 3/4" pinion stem and is correct for a '68. The 7 3 is the casting date July 3.

Installing a SureGrip unit in a non-SG housing isn't a simple bolt in, after swapping the ring gear to the new SG unit the bearing preload must be set using the threaded adjusters; the procedure is outlined in the service manual.

[firefighter3931]

The 742 housing is correct for a 68 charger. All you need to get is the clutch style SG unit and have it installed in your 742 case. The centrsection will need to come out for the suregrip install. That would be a good time to inspect the bearings, side gears etc...and replace anything if need be. A new clutch unit will run you ~ $400.00 and a complete bearing kit is another $100.00 or so.

Ron

[4402tuff4u]

Thanks for the reply guys. I did see them at Mancini for approx. $ 410.00. They had two types, both 30 spline type. One for street and the other called aggressive pro/strip unit. Thanks for the education on reading these numbers on the housing. Now have to save for the purchase and installation costs. It does make sense to basically overhaul the whole rear end unit, change bearings, oil, etc,... I should have check the oil in the unit to see that it's clean. Next time when I'm at the shop.