rear ends

[71chmark]

The one on the right is a 3.31 (742 case) non sure grip. I don't suppose it's worth anything?  The one on the left is a 489 case sure grip.  I count 43 teeth on the ring gear and 10 on the pinion which means 4.30.  I look at lists of selections and I don't see 4.30.  I see 4.10 and 4.56.  I've counted several times and am sure I'm right.  My car now has a 3.23 sure grip. I need a new drive shaft and the 3.23 has the smaller yoke while the 4.30 has the large yoke.  I don't plan on doing much highway driving (just burnouts and short runs).  I've had 3.91 gears in my old roadrunner and it seemed OK on the Highway for short trips.  Do you think I'll notice much difference?  The 4.30 has some dirt and surface rust but the bearings look OK from what I can see. Should I try to clean it up somehow?

[BS23VOB_FJ5_Faker]

I ran 4.30s for a while behind a 727 - If you ever want to go more than 50 MPH for more than a few minutes ata a time, you will not like them.

[tactransman]

I have 4.30's in my Chally and no it doesn't like highway cruising,but they get up a go. Get some taller tires for 'em and they will probably be fine for what you want to do.

[71chmark]

Should I just wipe it out the best I can and stick it in? The rear end I mean. Uh, the pig.  The center section. Oh, you know what I mean.

[ShelbyDogg]

Wipe off any loose rust. Use a can of wd40 to wash out any dirt on the bearings while turning them.  Install it.

If you are getting a new driveshaft with a different sized yoke as your pig, buy a spare crossover u-joint for later when you want to put your 3:23 gears back in.  Any good auto parts store can get you a crossover u-joint (big on one end and small on the other)

[Rare_T_A]

I believe this is the conversion joint numbers.

7260 to 7290 U-joint

--------------------------------------------------------------------------------

TRW part # 20226.

Precision 347.

Mancini Racing........... 5-527X

Auto Zone ........... 2-0527

NAPA ............... NUJ240-0369

[moper]

When I have a dirty centersection like that, I just tip it so the pinion is pointed up, and hose it out with some brake clean. Dirt and mionor rust wont slow it down. Sand or metallic grit will. Looks like they swapped in teh gears, because the old gears destroyed the pinion bearings. Thats teeth marks on the side of teh limited slip... So 4.30s will be a possibility. I like them, but unless you run a 29" rear tire, they will a bit to get used to on the freeway above 55mph. It's about 10% more gear. You'll notice it I think.

[71chmark]

Thanks a lot for the responses. They help a lot.