Jeep Strokers

Not sure where to start but I really need to get going on my stroker build. I’ve been planning on building a stroker for the last few years, but my current 4.0 has been hanging in there and I’ve had a few large expenses lately so I’ve put it off as long as I could. Last night I changed the oil on the ~250K mile 4.0 and saw quite a bit of bronze glitter and a few ~1mm chunks of shiny metal - no unusual noises or odd behavior, but it's just a reminder that this engine will not last forever especially with my use case. Which is as follows-

1996 Jeep Grand Cherokee Laredo ZJ 4.0 / 42re / NP242 – 250,000 miles – Denver, Colorado
-Used as a DD
-Used as a tow vehicle our ~2000 lb. off-road teardrop trailer up to elevations as high as 13,000 ft. for camping
-I also enjoy some moderate wheeling / rock crawling around Colorado and the 4 corners region a few times a year (without the trailer)

Current relevant mods –
- Kolak Ignition kit – MSD Coil, Magnacore wires, Autolite Platinum gapped to .040
- Kolak 3” Exhaust – Flowmaster 70 series and Magnaflow high flow cat
- Walker stock style downtube (for now. Custom 2.5”>3” mandrel-bent will go in with stroker)
- Doug Thorley Tri-y header
- WJ intake manifold with insulation kit
- 62mm bored throttle body
- Bosch 12 hole injectors (New OEM Bosch fuel pump)
- Ford 8.8 and Dana HP30 axles geared to 4.56
- 255/75R17 BFG Mud Terrain summer tires and 265/75R15 Cooper Discoverer M+S for winter

I REALLY need more power for towing in the mountains. That is the main goal. I would like to stick with 85 pump gas, but if 91 will yield significantly more power I am open to it. The 4.0 is a complete dog while towing up the mountain passes and I frequently have to downshift to 2nd gear (42RE transmission with upgraded solenoids / transgo shift kit) and sustain 4500 RPM for long periods to keep up with traffic (the 4.0 redlines at just over 60 mph in 2nd). I do plan on doing an AX-15 conversion at the time of the stroker along with a 231 HD.

I have the 4.0 from my first 96 ZJ that I purchased in 2010 on a stand in my garage along with a 3727 4 weight 258 crankshaft for the build. The 0630 head has less than 50,000 miles on it and I would like to work with that one – I really like the idea of a cast-iron head on the cast-iron block. Since my 96 is OBDII I will be getting a custom tune one the stroker is in. I also own a DRB III not sure if that is relevant or not.

As far as the rest of the specs – I would like to hear some input from the experts. I was thinking of reusing the 4.0 rods and getting Russ’ custom pistons, doing as much DIY porting to the head and I can and also would like to defer to the experts on the top end – bigger is better for the valves right? I also don’t know where to start for cam selection.

I have never built an engine but have been doing casual research for the last 3 years but really have no idea what I’m doing. I will be working with a local machine shop, but I haven’t picked on yet, and doing as much of the assembly as feasible.

Please help this novice with a stroker recipe for my use case!

After 250k miles of use, your stock rods will almost certainly need to be reconditioned and resized so I suggest you get a set of rods, pistons, stroker crankshaft, timing set, and camshaft from Russ. You'll also need new lifters, pushrods, valve springs/retainers/keepers, main/rod/cam bearings, oil & water pumps, freeze plugs, upper/lower gasket sets, and oversize injectors.
If you want a ported head, I suggest you buy a ported iron head with LS1 valves from Russ. He might even do a core exchange for your stock head.