grantpo

Recipe for motor build for my Jeep YJ Mud/Crawler that is on 41" tires and one ton axles 4.56 gears.

Stock 2006 LM7 (currently in the jeep and runs excellent!!) want more power though and can't afford a 6.0.

Parts collected so far.
Flat top pistons and rods from a GenIV 5.3
LS1 head gaskets
799 heads rebuilt with Brain Tooley dual springs, milled .020, and 3 angle valve job.
NNBS intake, 87mm TB, and X-Link
EPS cam 210/212 .604"/.604" 112 LSA

Currently has a Muncie sm465 trans that is great but with this motor I really need an auto, so will probably switch to a 4L60e cant fit a 80e. Will most likely never see over 5k rpm.

Some questions I have:
1. If you have any input, advice, HP or CR predictions can you please share?
2. If the motor is running like new now, then when I swap pistons all that should be required is a hone and new rings right?
3. Or could the current rings just be swapped to the new pistons?
4. If I switch to an auto 4L60e what stall would you run?
5. Are the stock 2006 lifters and rockers good enough?

Wolftrk99

iTrader: (5)

Do not reuse the rings, if the bores all measure within spec and dont look worn honestly wouldnt even bother honing just new rings and call it a day, honing can take more mareial off than you want!!! Rockers should be fine, consider a trunion upgrade though, and at least a set of ls7 lifters.. As far as stall talk to the converter manufactures abd see what they recommend but id say at least 2600 or so...

mikeyjm1

I'm gonna hang out and watch this. My wife has a 95 YJ that I've been dying to swap.

grantpo

1989 YJ "CL and Junkyard Parts" Frankin build - JeepForum.com

Here's a link to the jeep in question

grantpo

Thanks for the reply. I hope I can get away with a smaller converter. 2600 might be a pain on the trail at low speeds.

Wolftrk99

iTrader: (5)

Again i would call circle d or tci or whoever and see what they say....

mikeyjm1

I was about to mention that you first said "Mud/Crawler" and on cam and stall those are two different ends of the spectrum. If you want a mud truck it can have a high stall and spin to the moon but, a rock crawler needs to be able to ease off just off idle without spinning or actually stalling out. So the lowest possible stall would be best there.

Wolftrk99

iTrader: (5)

Which would need a cam with a powerband that is quite low as well, youd almost want your powerband to hit between say 500-800 and top out somewhere in the low 5000 range.... In that case you would want more like a stock stall i would imagine.... I have a trailblazer stall in my truck and it is actually a bit higher than i would want for crawling vs an all out mud truck.... For what youre doing with the truck you want all your power low and shitloads of bottom end torque.....

grantpo

Yes you are right. Let me clarify what I mean. I live in South Louisiana so no rocks. And I'm not into the raping of the rev limiter mud riding in a open field. We trail ride in the woods going slow, which yes you do end up getting into some mud or whatever and have to open her up some. Also its driven alot on the streets.

Wolftrk99

iTrader: (5)

Stay somewhere around stock stall, my 99 on 35s with 4.10s will pull hersef out of anything so long as i dont have a set of ties on that were meant to dig (i.e. Superswamper tsr's) i run a meaty all terrain like the kumho at and used to run dunlop rover rv until they changed them to the rvxt when goodyear bought them... Just keep in mind the more power you have the more youll dig....