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Discussion Starter #1
Should I go with 39.5" IROK or 42" IROK ?
The current specs:
318 engine, not a lot of power to spare!
TF727 tranny with 2.45 1st gear ratio.
NP 208 transfer case with 2.6 low range.
Old gearing 4.56/ new gearing 5.86
Old tires 38.5 tslsx

So, 2.45* 2.6* 4.56 = 29:1 crawl ratio
2.45* 2.6 * 5.86 = 37:1 crawl ratio
These are without taking into consideration the torque converter.

There is about a 28 % gain in crawl ratio.
There is about an 8 % difference between the 38.5 actual tire diameter and the 39.5 and about a 14 % difference between the 38.5 and the 42" so, I should feel some overall gain, right???
I really want the 42" for the extra ground clearance but without some modifications to the engine I am not sure if I should just get the 39.5" IROK and be happy?
I have come to really love the rock crawling the most so the ground clearance is becoming an issue but without the reliable power to turn the tires it creates a safety issue. Could do propane or add fuel injection i guess but there goes lots more money.
Comments please, and be honest!
 

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For some reason is shows I already voted, but I didnt. :?

I say go with the 39.5s.
 

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42s--I think with the 5.86 gearing your 318 will do fine. You will eventually, sooner than you think probably, get fuel injection or deeper t/c gearing. IMO you really need the clearance the 42s will allow.
 

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Get the 42"!
A) You have the room needed to run them, without alot of body mods.
B) They will make your rig look bigger and better.
C) Crawl ratio does no good if you hang up on every little rock that sticks up. (like the other day)
D) I know you are wanting fuel injection so I see and engine swap before much longer. :) I know the 318 has been acting up on you.
E) The stuff we have been running doesn't need a low crawl ratio, and your carb keeps you from going to straight up.
F) Is being Married really all the great?
G) Even running the 42" tires you should gain more power than you have now.
 

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Mas Tequila
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44's
 

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I've met Johnny Cash
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Rastus said:
Agreed. Do it and get it over with. Those monsters are all too expensive to fool around with stepping up a little bit at a time. With 44's you will be at the limit of 1 ton running gear anyway and so, the tire issue will be solved for good in one stroke!

rockonn jamminzz bigok smokin
 

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Discussion Starter #12
gee

Thanks Kenny, Greg, Kling-on & Stretch, Now, what armored truck shall I rob to fund this?
tssl tssl tssl tssl and a sparetssl
 

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dont forget the kune v


and I respectfully disagree with mudgod on the crawl ratio thing, we got to the top of that hill and the tires wouldnt turn due to not enough low gearing and that was a scary feeling. with my crawl ratio and 62 horsepower i can crawl up a 90 degree wall until I turn over backwards. so crawl ratio is very important in rock crawling.
 

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I say 39.5's, same tire as me and then I can say.......well Old Goat, we have the same size tires, why am I the only one up this hill? 2finger
 

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Discussion Starter #15
hmmm

Going with 42" for sure now, lol
 

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TX_ZUKI said:
I say 39.5's, same tire as me and then I can say.......well Old Goat, we have the same size tires, guess we both need to get bigger tires since STRETCH is the only one that made it up that hill with smaller tires then both of us? 2finger
LOL
 

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TX_ZUKI said:
I say 39.5's, same tire as me and then I can say.......well Old Goat, what happen to Stretch he was right behind us? 2finger
What I meant to say!
 

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Discussion Starter #18
!

lol lol lol jamminzz I just put that punk rocker smiley in because he is the coolest.
I hope we can all get to the top of the hill and celebrate with a cold beer

Seems it is neck and neck between 39.5 and 42 with really good points to consider for both. That is why I did the poll to get other good ideas, keep em coming, I am ordering something this Monday the 21st.
 

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add some 5.38's and spools to that order please

for real, I would go to the 42's and be done with it for good. if you go 39.5 in six months youll want 42's. the 60's will handle 42's so do it.

we'll have you a klune v or atlas before long to make up for the loss of power.
 

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Discussion Starter #20
yep

It is settled, ordering the 42" IROK tires on Monday the 21st. A big problem has cropped up on the front d60 with the broken off bolt, cannot get the old bolt out so drilled and tapped it with a 1/2" grade 8 and praying it will hold with the U bolt and the other good 9/16 bolt. Many thanks to Mudgod for lots of drilling and hanging in there to help me out.
 
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