DirtyComanche

Leaf spring rate is mostly a function of the number of leafs, their thickness and width, and the length of the pack. More leafs, more spring rate. Thicker, more rate. Wider, more rate. Longer, less rate. Static arch does increase the rate by a small factor, although it is an exponential relationship. That is, within the realm of flat to a moderate amount of arch, say what the factory 4wd springs are, there is a very minimal increase from it. As arch is increased beyond there, the relationship starts to become more apparent. This is part of the reason why many aftermarket mondo lift springs ride poorly. Wrap/anti-wrap characteristics are a little harder to pinpoint, as they have to do with the relationship between the three mounting locations, the vehicles CG, the spring rate and configuration of the leaf pack, and about 8 billion other little things. In general springs with MORE static arch display WORSE wrap/anti-wrap characteristics, but that's a statement that really can only be applied once the arch becomes quite significant. The other part of the reason those aftermarket mondo lift springs ride poorly is they added spring rate to try to fight the wrap issues. Flat to mild arch (positive or negative) springs typically perform best for everything. But there's some give and take with that statement. If you want to go fast, have a lot of power to deal with, and are rule limited in regards to wrap control, and have no huge issues with ground clearance, often a spring under setup with more arch will perform better than a spring over setup with minimal arch. From a standpoint of what we're probably doing, and if you're looking to add that much (3"+) more arch to the spring pack, it isn't likely the case. I only have a set of factory 2wd MJ springs to measure. The spring pack is only 1.5"~ thick. Add that to your axle tube (2.75") and a bit for the perch (.75"), and you're at about 5". The 2wd springs are at least an inch lower than the 4wd ones (static arch), so that means only 4"~ of lift going from a SUA 4wd spring to a SOA 2wd spring. Obviously there is variables in play here, some axles have larger/smaller tubes, many spring perches are taller, some people add an overload, not all of the factory springs are the same, or even close, vehicle weights vary, some people can't hold a tape measure, etc. The GM springs I mentioned are from 2wd trucks and are fairly flat, but I don't have a set to compare. However, they're available with many different amounts of static arch and in different rates, and you can tune them with other flat springs (F-Junk, Wagoneer, whatever). They aren't perfectly the right length (they're missing an inch behind the center pin, which is significant), so one might have a headache using them, but I'm confident they could be made to work and made to perform well. But thanks for wishing me luck, because I intend to be playing with this setup this fall.

Neither of those things are particularly related to the static arch of a spring pack.

Is the pump actually running while you're cranking? If the fuel in the lines and rail was really that bad, there is a good chance that multiple injectors are plugged, and the regulator is gummed up. You could keep trying it and they may flush themselves out enough to function, or they may not. Even if you're down two cylinders it's really hard to get the engine to start. Check fuel pressure while cranking, look for it bleeding down.

Not if you're using springs that are effectively lowering springs.

Now, if you really wanted to be different, I think you could use 56" Chevy springs (73-87 2wd trucks) and install them SOA. They don't have much static arch, but are obviously a little stiffer. Also, SOA with 2wd MJ springs should only be a 3.5-4.5"~ lift on a 4wd truck.

That too.

3.5" of lift from shackles alone isn't really a great idea, IMHO. I'd get some S-10, Dakota, or other MJ springs and steal the main leaf out of them to add to the existing pack (cut the eyes off it), and then add the needed length of shackle.

Did it run before you replaced the tank and pump?

Normally you can just weld them up without doing anything special, the metal is plenty thick. Most of the flex pipe stuff is meant to be welded in, but some can/should be clamped. It depends on the style.

I believe you can still order a GM 1 ton truck with a 6spd. You could as of a few years ago at least. They're hens teeth used, but they're out there, pretty fun combo of the Duramax and a 6spd manual.

I wouldn't go out of my way to source a NV3550. The Teralow is a pile of junk. I wouldn't run one if it was given to me. Go with the NP241OR, It is actually reliable. The Teralow has an unpublished maximum input speed while in low range, and it's quite low. The Teralow absolutely won't last behind a doubler. The NV241OR, well, it should, although you're definitely asking a lot of it. I have a NWF EcoBox and Ford NP205 in my XJ. Yes, it will mate up, that's the intention of it. They actually won't recommend that you use an aluminum case behind it, if you really ask. There is serious downsides to this setup. You can't clock the NP205 up high enough to get anywhere near a flat belly, unless you're super short or willing to run some terribly uncomfortable race seat, and that's after cutting the entire mount boss off the NP205 and plating over it. I modified my seat mounts extensively, and spaced the seat up, along with doing a massive realignment and patch job on the floor. Clocked as is, it moves the driveshaft over a bit to the driver's side vs a NP231, which probably won't cause you any issues, but coupled with my front axle it meant the entire floor had to be cut out and changed. It also might be hard to fit your typical long arm setup in, but YMMV, my XJ is very low for the tire size (maybe 4" lift at most). Also, the entire doubler and tcase setup is something in the range of 175lbs (I'd have to look, I have the exact number somewhere), which means you're absolutely not going to get away without having a second mount, and it's just heavy in general (keeping a vehicle light is extremely helpful for everything). You really will need to go to polyurethane motor/trans/tcase mounts to deal with the torque. Also, there isn't an actual regular twin stick shifter available off the shelf for this setup, just cable shifters, which I hate, so I spent a bunch of time/money making a twin stick setup for it. You'll need a speedometer adapter from PATC, I can get you the P/N if you want. To do it over I'd just buy an Atlas, honestly, I have way too much time and money into this once you figure out all the monkeying around with cutting holes in things, rebuilding things, and fabbing one off parts.

Honest opinion. It isn't worth it to go to an aftermarket header. Just have the stock one welded. Or buy one of those really cheap stock replacement ones that perform worse than the OEM part. The problem with the Renix is that it uses its own header, as it has both an EGR and O2 bung in it, so the HO ones will not exactly work. If you can delete your EGR (not sure if that's really an option for you, since you have emissions testing) and go to a HO header and downpipe/midpipe, it opens up a lot of options for aftermarket exhaust. Otherwise you're pretty much stuck with Walker replacement stuff, or having it made, or making it yourself. There is some power to be gained by going to a good aftermarket header, but I don't feel it's great bang for the buck, and many of them are troublesome to fit and have the same cracking issues as the OEM part. Also, some of the HO aftermarket headers will not clear the Renix intake manifold, and some will not even clear the early HO intake manifold. I run into more trouble than I wanted when I bought a cheap Amazon stainless HO header and bolted it onto my Renix engine, wound up having to convert to a HO intake plus do some custom clearancing. I wound up building my entire exhaust system using a couple sections of 2.5" straight pipe and some J-bends that I bought from Summit, since I wanted stainless and the local shop quoted me $1000 for materials alone. (I think it was under $100 for all the material from Summit, with leftovers).

It will probably be easy for you to just swap all of the 95 XJ stuff in, including the manual transmission. The AW4 automatic is a very good transmission though, so if you wish to keep it you certainly can. However, there will be wiring differences that you will need to address, and I'm not sure how easy it would be for you to find an automatic wiring harness that would be compatible in your part of the world.

There definitely is a difference in quality between Moog and the discount junk. That said, is it good value with the price difference? I don't know, but for harder to change parts I feel it is worth it to avoid having to do a job again sooner. There isn't any reason that parts made in Chindia can't be good, but it is up to the manufacturer to actually have and enforce QC standards.

Exhaust leaks are not likely to throw off the O2 sensor, as the pressure in the exhaust is normally higher than ambient (as in, the exhaust leaks out, not clean air leaks in). Your header is probably cracked up in the back where a couple of the tubes join, they all do that over time. If it's a really massive leak (one of the tubes has broken right off) it could possibly be affecting things though.

Any idea how different this is from the comparable V8 ZJ part?

Good to see this thing is still around. :cheers:

You'll need a Photobucket account or something like that. Check this out: http://comancheclub.com/topic/37727-how-to-post-pictures/

I hate exhaust work. Good luck.

Yeah, kinda. If you can see the pattern on the gears you can just adjust so the pattern is the same. I would then verify that backlash is still in spec, you only need a cheap dial indicator and magnetic base to do it. If you can't tell the pattern you're kinda screwed. Adjust to the best pattern with backlash in spec and run it to see if it is quiet or not, it may be fine or you may have to do trial and error changes from there to get it quiet. If the shop that set it up recorded what the backlash was set to you can just return it to that also.

Factory?

The vacuum lines on the airbox air for the intake heater valve junk. You can delete all of it, as it won't be doing anything with a CAI. Be sure to cap/plug it at the manifold. No comment on the floorboards.

Get you a cover for the front and rear for $200. Pricey, but a better deal than otherwise. Debating ordering a D30/D44 set for either my JK or MJ. Maybe I should just order two sets. :rotfl2:

I've already purchased an SYE kit for it. I'm retroactively updating this thread, as I've knocked out a ton of work on the build so far. I just haven't had the time to post! :thumbsup:

Oh, that newer style tcase uses a different slip yoke than your 2wd driveshaft, if you were just planning on getting the 2wd driveshaft shortened.