Yet again! my H55 question

[El Cazador]

I'll be using my '74 FJ40 for hunting mostly; some daily driving to & from work when weather permits. So, long drives up I-15 and out the 40 to the Mojave National Preserve. Dirt roads, some can be plain nasty, but many wouldn't tax a Mercedes SLK. Ain't gonna be doin' no rock crawlin'. Other than the "cool" factor, does it make economic sense to sink the dinero into the H55 and the xfer case for how I'll be using this truck? Is it gonna give me noticeably better mileage by running in 5th? Engine in it is a rebuilt F. I'd like to do it, but for me it's some serious money. What could I expect to get out of the 4spd and xfer case in it now assuming it's in decent shape?
Vic
Redlands

 

[okie]

If ur not gonna rock crawl i I am thinking about just changing the gears instead of doing a 5 spd. I think its cheaper by alot. I have heard from some people that when they do the 5 spd the 2f in 5th gear doesn't have enough horsepower to really get along and it kinda struggles to GO if you know what i mean. Just a thought

 

[FJ40Jim]

The complete H55 swap into an early truck is a lot of $$$, plus the hassle of changing draiveshaft length, dealing w/ the P-brake. If you need to slow the RPM's on the highway, first thing is to do a rubber overdive. Changing up to a 33x9.50 tire will drop RPM quite a bit compared to a stock 28" tire. Or you could swap in a set of 3.70 diff gears and some 31" tires.

Either of the above would improve highway cruising without breaking the bank.

 

[65swb45]

Vic, as someone else who frequents the East Mojave, I concur with Jim C: a 4 speed tranny and a rubber overdrive should be more than sufficient for your backcountry needs.

 

[El Cazador]

Yeah, makes sense to just use the larger dia. tires. Maybe the 3.70 diffs. Thanks for the dose of common sense.
BTW, I have no idea what the ratio is for the diffs on this '74. Is there something to look for on them that will give me a clue?

 

[65swb45]

If the carrier nuts look as old as the rest of the truck, you can assume they are 4:11s.