gear ratio?

[cowboymike51]

ok i have a 72 gmc k20 with a 6in lift running 35s, now i have 4:11 gears and i was thinking about going lower to maybe 5:13 or lower. now its pretty much my mudd truck, i us it for play, i hardly ever take it on the highway and if i do i barely even hit the 55mph mark, i try to save gas were i can. now would the lower gear ratio help me with my muddin

[shilo]

what size engine and where is its power band? Also what kind of tranny?

[cowboymike51]

oh its a mild 350 with a rebuildt th350 that i build my self at school. power band is all lowend

[shilo]

4.11 are probably just fine. unless you got the extra cash 4.88 or 5.13 would definately help. But if your paying a grand to put gears in, you could get a locker or two which would be more better in the mud than a little lower gear. Id go with lockers now, gears later.

[79BRUISER]

As far as the tire/gear calculator is concerned, your 4:10 gears are right on the money. If you plan on getting larger tires, a gear change might be in order.

If your happy with the current tire size you have, then I would install a detroit locker in the rear. Or weld it.

I am swapping 3/4 ton axles into my K5. They have 4:10 gears in them. I plan on welding the rear 14 bolt and leaving the front 10 bolt open. I'm also going to run 37" boggers.

One day when I have the $$$ I will replace the 10bolt with a dana 60. Or might just go with Rockwells.


Bruiser

[vtblazer]

Originally Posted by cowboymike51

ok i have a 72 gmc k20 with a 6in lift running 35s, now i have 4:11 gears and i was thinking about going lower to maybe 5:13 or lower. now its pretty much my mudd truck, i us it for play, i hardly ever take it on the highway and if i do i barely even hit the 55mph mark, i try to save gas were i can. now would the lower gear ratio help me with my muddin

I'm running 5:13's with my 42's, thinking it'd be terrible low with those 35's for the street.
Playing might be okay but your going to run out of wheel speed fast and in mud, wheel speed is where it's at if your serious about playing in the mud.
If you stay with 35's invest the money back into gaining horse power maybe, not the best bang for your buck installing gears IMO.

[LONGHAIR]

What ever choice you make about the rest of this............don't weld the spider gears. If this is really a "toy" that doesn't see highway use, a locker is probably the best way to go. The cost factor is greater in the begining but welded spiders will cost you more in the end.