Gear swaps in my 5 speed SX/4. Suggestions?

[MortenB]

My SX/4 has a 5 speed manual.  In reality, only the first three gears get used.  The speed limits around here (central Norway) are 40-50mph.   340 miles away I can find the closest 62mph speed limit.  (never been there with the car).  So, I would like to change the ratio and get a locker for the rear.   What are suggestions on ratios for the axles that are straight swaps?  Where should I get a locker for the rear?  Are there lockers available that can be manually locked in addition to automatically locking?

I have a Jeep Cherokee parts car ('89 ish) that might have usable gears.  Haven't checked the ratio there.  (the idea with that car was to swap over the fuel injection, but when I went to get that project going, I couldn't get the Jeep started (I drove it home 6 years ago).   I took that as a hint to stay with the simplicity of a carburetor).  I need to get rid of the Jeep soon, so if I want parts off it, they need to be pulled soon.  I know I will pull the transfer case; what else?

Anyway....the high gears make the car doggy off the line.  It would be fun to be quicker, and with the 5 speed I would still have low rpm at 50mph.  I just put my spiked winter tires on, and noticed that they are over an inch higher than my summer tires.  That just made the car even doggier!   All suggestions are welcome.

[carnuck]

4 or 6 cyl? Tire size?

[MortenB]

6 cylinder.  205/75/15 and 215/65/15 are what I am using.

[priya]

Some (all?) 4 cyl eagles came with 3.54 gears, that should get you what you're looking for.  I have 3.07 gears in my SX/4 and its pretty snappy off the line and revs a little higher than I'd like with the 3 speed auto at 100 kph.

[Draekon]

I have 2.73 gears in my 6-cyl 4-speed SX/4.  It would be nice to have a little steeper gears, but would only do that if I swapped in a 5-speed.

I would recommend going for 3.07 or 3.54 gearing.

[carnuck]

So if that XJ is a std trans 4.0L, it will be 3.07 most likely or 3.55 if auto.

[MortenB]

What is my stock ratio 6cyl, 5spd?  Will gears from a Cherokee swap right into the carriers?

[eaglefreek]

What is my stock ratio 6cyl, 5spd?  Will gears from a Cherokee swap right into the carriers?

The 4 speeds usually came with 2.35, not sure what the 5 speeds came with. Dana 35 gears will install in the rear, but the front's won't interchange. The XJ used either a short low pinion or a high pinion. You need Dana 30 long low pinion gears that were found in CJ's and some other older vehicles. 

[carnuck]

Only the last couple years (2000+) XJ had low pinion front. All ZJs and most TJs were low pinion (except Rubicons) Volvo also used long, low pinion D30s. Depending on tire size, 3.08 with stock size or 3.55 with slightly taller would be the way to go unless the rear is a rarish 2.72 D35 (export XJs only).