4.0 head swap questions

[EagleJoe93]

Good news; I've finally found a local salvage yard that carries older vehicles!  I went there this morning and big surprise, they had nothing made by AMC, not even a Jeep. But they did have some grand cherokees with the 4.0 six cylinder. For yucks I asked how much the head would be and a few moments later I was offered the chance to get the head, valve cover, exhaust manifold, and intake manifold for $150 and that was without negotiating.  I know after reading some 4.0 head swap posts that I can use my original intake manifold, but my questions are aside from the parts mentioned; is there anything else I would need for a swap? Posts say that 91-95 4.0's are the best, but the one I saw was a 96. Would this model year still work? They had another one but I don't know the year. Is this a good price for all of the parts? I know that the swap will greatly increase horsepower, but are there any other benefits to the swap? I plan to go back there tomorrow with my dad. They also have a front bumper for his 2000 Dodge Grand Caravan (the car I've been driving until my Eagle is fixed).

[mudkicker715]

That exaust manifold is going to be a b i t c h. unless you are creative. i made it work if i can well  good luck. i am a retard

[carnuck]

The computer won't work. Grand Cherokees are a (insert dirty word here) wiring nightmare with doorlock sensors and key fob codes, ect. '96 is a crossover year OBDI and OBDII and as such is often a problem child to boot. Different year exhaust manifolds have different outlets too.

[EagleJoe93]

So I'm getting the sense that I should pass on this then?

[mudkicker715]

No matter what jeep head you use the exaust is a bit  ch. Unless you use the eagles whitch negates what you are hoping for

[vangremlin]

If you're not planning to switch to fuel injection then the fact that the computer won't work shouldn't matter.  I'm not sure if that head is a good one to use, you might hold out until you find a 91-95 - they're pretty plentiful around here.

[EagleJoe93]

I'm not planing on switching to fuel injection. They had another Grand Cherokee there aside from the 96 but I don't know what year that one is. If I can't get a head would it be a good idea to get everything I need aside from the head off one of the Jeeps there?

[DaemonForce]

My plan is to carburete a 4.0L and then do LP/H injection. I just finished sealing off my ported vacuum, retired the air cleaner system with a rusted chrome donut and fixed a bunch of vacuum leaks. I'm at the point where I should swap exhaust headers and the head tomorrow. How much work is involved? Should I go grab a 6 pack or 12 pack of beer for this one? I can already tell I'm not going to like the exhaust work but it has to be done. :/

[vangremlin]

If you just want to swap the head, I think all you'll need is the head, the valve cover, and the exhaust manifold.  It will still be a lot of work to get the exhaust to work.  I haven't done the swap yet, several members (including carnuck) have, and I believe their opinion is that you also have to swap the cam and do the EFI conversion to get the most benefits from the swap.  But I'm not sure about that and will let them speak for themselves.

I'm trying to find a link regarding the swap, which I'm sure is in one of the threads on the Nest, which provides lots of details about the swap.

[EagleJoe93]

I guess I'll see what I can get if I choose to get anything. If I can't get the parts and do the swap that is fine I'm in no rush. I'd like to make this as good a driver as I can since I'll be depending on it to get me to school but money is a little tight for me right now.   I may be going back there tomorrow anyway because they have a front bumper for my dad's Grand Caravan. It seemed like I could get everything I needed for a decent price. What is the exact problem that people have with the exhaust manifold? I have a bunch of Flexpipe leftover from the temporary fix to get my eagle home. Would that be helpful in any way?

[carguy87]

I would highly recommend doing the camshaft while you have the head off, you can remove the lifters, then the radiator, and pull the camshaft straight out, unless you have A/C, you would have to move the evaporator then too.  Any exhaust header can be made to work depending on your skill level.  I used a 95' on mine.  The challenge is that it opens up and points straight towards the front drive shaft.  I used the upper probably 5-6" of the 95' pipe to turn left then a few pieces of pipe I had laying around to then go down between the frame rail and the drive shaft and just turned back into the existing pipe on the AMC.  As others have said, the FI is a must to maximize, but isn't required.  It is also another $3-400 roughly to do and a fair amount of time depending on your wiring experience level.  It will get rid of the high idle in winter to warm up, makes it easier to run accessories, changes in elevation are accounted for automatically, and it will run a little smoother with a more even fuel distribution.

[EagleJoe93]

Thanks for all the help everyone. As it stands now, I will not be doing the swap anytime soon mainly because money is tight for me right now and there are more important thing to do to my eagle than the swap (get it running).

[carnuck]

I'm putting a carb on my 4.0L HO motor (from a '93 Grand Cherokee that I put in my '84 J10) with HEI dist until I can get the wiring harness parsed down to do my EFI swap.