new tires/gears

Not sure which forum to put this in which I will explain as I explain what is done to the truck and will be done.

Current set up is a 2004 ram 1500 6 inch bds non torsion drop lift, 3 inch body lift and pre runner fenders running 38/13.5/17 tires, being pushed by a 5.7 hemi with header back exhaust, diablo sport tuner 93 octane set up, procharger 6-7 psi, 4.56 gears, 545rfe auto transmission.

The problem is I keep breaking stuff with my half ton ifs front diff, sheered front drive shaft, cv axle came off diff (not even at an extreme while sitting just lots of travel), and one time I hit rutt and ended up breaking almost everything on front drivers side (spindle, lower control arm, sway bar link).

So what I am doing to fix this is putting my chassis on a 2004 dodge ram 2500 dodge ram frame, eliminate body life and do either 6" or 8" coil over shock lift, and looking at running 38.5/14.5/16 wheels maxxis creepy crawler which with a 12 inch rim says will be 38.8 diameter.

I am going to make that frame and suspension work with 1994 4x4 dually axles dana 60, and dana 80 with trusses, for strength as well as the option of lower gearing. My 4.56 with 38's set ups currently is under powered at low rpm I constantly run tow haul to keep from going below 1500 because it feels gutless until about 1900-2000 rpm anyway. So I am split between 5.13 and 5.38 gears I don't do much highway but I did look into that it says with overdrive at highway speed 110 km/h(max speed of tires is 120) 5.13 would be 2034, 5.38 would be 2134 so neither is horrible. What would you suggest I run?

Well since you're doing all this work, you may want bigger tires in the future. I say go 5.38s. But first order on the list, post up some pics of your truck, it sounds awesome.

Yea that close ya might as well go with the 5.38's. And I agree we need pics lol

I have 5.13. Perfect for 38s. Lol.

I got a picture album and signature and profile pics of it, but it won't let me put in msg it wants me to insert a website link and it's saved on my computer.

Ya I guess might as well do 5.38 but I think i'm going to be limited on tire size due to height without putting body lift back in. Also not sure how much higher I can go and keep it street legal, I think 3/4 chassis naturally sits like 2 inches higher so with 8 inch kit I will be 1 inch higher then current 9 and a little from slightly bigger tires. Kit says it clears 38/14/17 on 17x9 with 4.5 inch back space , I'm going to run 38.5/14.5/16 on 16x12 rims(tires need min width 11 inch) with 4.5 back space+ however much extra width from it being a dually front end. Smaller rims should work because older axles min diameter is 16, and I have to do a min 11 wide for the tires so had to go 12. I think I should be good for the little extra i'm putting on because the pre runner fender kit gives me quite a bit of added clearance like with my current set up without my fender I wouldn't clear 37/12.5/17 without maxxing my torsion out (know another guy with exact same lift set up and reg fenders had to do this) and right now I clear 38/13.5/17 with 2 inch spacers and could maybe clear 40's.

I was kinda leaning toward 5.38(deepest gearing possible for the axles) on the charts I was looking at (http://www.offroaders.com/tech/gear-ratio-chart.htm) puts 5.38 as too deep for 38's but in the high green for 39, from what the charts say the tire diameter measures at 38.8 on a 12 inch rim(https://tiresize.com/tires/Maxxis/Creepy-Crawler-38.5X14.50R16.htm) so it is almost 39 cause most tires I've bought always state they are taller on sidewall then charts say my current is 38 chart says 37.7 but on 11 inch rim I have 9 inch(https://www.yokohamatire.com/tires/detail/geolandar_m_t_plus) Just figured i'd check to see if anyone has done anything similar and had advice.

Hard to make a comparison with you though joe between 8L displacement and 2 more cylinders your power band always gonna be a bit lower like trying to compare to a diesel running 38's. Although I still have a couple questions like, auto or manual? and where do you find your power band starts? Also where do your rpm sit on the highway?