Time for my '87s new rear end...

[deesandvees]

It's time for me to decide what to do with my rear end, and I don't know much about that end of things. I will be bringing it up to the local Ring & Pinion soon for a posi install. Not sure what the gear ratio is in it now, most likely factory so whatever would have came in an '87 Landau with a 305 and a 200r4.

Now it has a 383 in it and a 700r4. It's a little slow off the line but once your at about 25mph it wants to get to 50 in a hurry. Overdrive on the freeway is very conservative on the RPMs but if I'm in the mood for changing lanes and getting on it I leave it in 3rd.

I don't want to sacrifice too much top speed (although I don't need any more 100mph+ speeding tickets). I think what I'm wanting is a something that gets off the line a little faster but isn't at 3 grand in 3rd gear doing 40mph. What gear ratio should tell the shop to do?

[MagicRat]

I think a 3:23 rear end would be a fine compromise. This would give you a 3rd gear cruising rpm of about 2800 rpm at 60 mph, with the tires you show in your pic. This would be fine for acceleration, trailer-towing etc. but would leave you with a relaxed 1950 rpm OD cruise at 60 mph.

[deesandvees]

What are some of the other ratio options and what kind of performance do they give?

[scuddigi_687@yahoo]

Aight my car is a 93 caprice, the original rear end was a whack 293's in a 7.5 housing. Knowing that I swapped for 373's but kept breakin the ring gear, never the pinion. Gettin inside knowledge I swapped for a 8.5 housing out of a 95 LTZ and installed 410's. Now I know you said you wanna cruse in low rpm's 410's will not help 373's in a larger housing should put you in a comfortable rpm and off the line take off. Before my 305-350 swap those gears made my baby,(car) run beastly but humble when on the highway. You may have the 7.5, GET RID OF IT. GET A 8.5 housing they are not the strongest but take better abuse and have a wider range of gear options!