Cherockee

I'll do that. Thought I'd be going there tonight but got called to do a remote starter so my plans for tonight have changed.

5-90

The head screws for the 6-242 are 1/2"-13 UNC (probably 2A/2B fit,) with a standard (1/2") shank. Nothing really exotic, except the "stud heads" on the driver's side for supporting the wiring standoffs for the F/I subharness and attachement of ground strap at the rear.

There doesn't seem to be enough heat to damage the F/I subharness if it lies on the manifold - you can always make a channel out of sheet aluminum if you're worried. That eliminates the need for the standoffs.

The ground strap may be attached to any convenient screw on the engine - I often move it to the rearmost fuel rail mounting screw, to make it easier to get to. So, that eliminates the need for the rear stud (it can hold the clip for supporting the CKP harness and keeping it away from the #6 exhaust primary, but that's nothing insurmountable either.)

Given that, and the looks of the head markings I've seen, you can probably then use standard (quality! Don't bother with Chinese or suspected Chinese...) SAE8 screws or SHCS of correct dimensions (SHCS = Socket Head CapScrew - these are routinely H&T to SAE8/ISO10.9 strength.) I have yet to try this, but if I couldn't use studs, I'd use SHCS and hardened washers under the heads.

Cherockee

Updated for information purpose:

It appears the the head bolts are identical between the newer model engines and the older model enginges. I removed a stud from my '95 block and went to the local auto parts store and compared it to the head bolt kit listed for 96+ 4.0L motors. Same length and thread count- absolutly no difference. Guess I can inform all the manufactures that they can now increase the range of years they're head bolt kits will fit. Thanks for everyone's input.

Now, should I swap the cam from the '97 motor or just leave the '95 cam in place?

SeriousOffroad

The head bolts on your 4.0L 9and 2.5L too) can be re-used one time. it's even stated in the FSM.

The differences between the various years (91-00) have to do with web thickness and the addition of a main bearing girdle in 96. The blocks and heads are all interchangeable.

Gee oh Dee

I'd still suggest using studs if at all possible.

But if you don't have the cash, thats a good thing to know.

SeriousOffroad

Why? there are hundreds of thousands of 4.0L motors out there with 200k+ miles that are still going strong with OEM head bolts.

We're not talking about a full-on race motor hat's gonna have the head removed after every 3rd 1/4 mile jaunt.

Studs in a stock 4.0L makes no sense at all.

Gee oh Dee

Yeah, using good/better parts if possible make no sense.

Wait....

SeriousOffroad

How exactly are studs better in a stock motor.

Objective evidence please, not subjective.

Increase HP?
Increase in Tq?
Increased fuel economy?

Piece of mind? "I've got studs...I can go anywhere and never get stuck!!"

Patiently awaiting your reply.

Gee oh Dee

Um, how exactly are head studs gonna keep you from getting stuck? Did I ever associate head studs with traction and off roading ability?

No, I did not.

I'm sorry you feel so strongly about head bolts.

But in the end of the day, studs are indeed better than bolts. That is fact.

But, you know best about everything, so sorry for suggesting someone use head studs if possible. I don't know what came over me, thinking I'd suggest something you don't like. I better never suggest anything ever again, especially the use of head studs.

Now does that make you feel better, big man?

Hope so, because I still like head studs, and if I have the chance I'll use them.

And keep suggesting the use of them if it is indeed possible.

How about you tell all of us why it'd be bad to use head studs over head bolts?

SeriousOffroad

Make me feel better? That's not relevant in any way shape or form.

You suggested studs because you believe them to be better. I disagreed and and asked you to prove to the OP, myself, and anyone else reading this thread why studs are better for a stock 4.0L motor. All you've been able to come up with is that you "think" they are better.

Don't get pissed at me because you can't give a valid reason for your assertion.

As I stated previously, the stock OEM bolts are fine for a simple head swap on a bone stock motor.

If the OP were building a racing engine or a very high compression then you're suggestion would have merit.

Gee oh Dee

I bow to your superior head bolt vs head stud knowledge.



I'll tell you why they are better when you tell me why they are worse?

Down sides?

Are they gonna ruin something?

I don't believe they are better. They are. Cost aside, anyway.

They can be used more than twice and they can provide more clamping power on the head (although not necessary on a stock motor, I'll give you that).

The only down side is price, at least that I can see.

I'm sorry you want to use parts that are of lower quality even though better parts are available.

I guess I just don't like cutting corners if better parts are available to me and I can afford them.

Like I said earlier, if its possible I suggest using them. If you don't have extra cash for obviously better parts, sure, be cheap like you are and reuse your parts.

I'd still like to know what bad could come from using them.

SeriousOffroad

They are worse for a very simple reason, they are not needed and a foolish expense for any stock motor. Take a look at the shear number of 4.0L motors produced and compare that with the quantity of 4.0L head bolt failures that you've heard of...then do the math and figure the percentage.

Now justiy the added expense for components that do not benefit the vehicle in any appreciable manner.

I'd rather add chrome, it does as much good and looks better.

Gee oh Dee

It seems as though you are confusing "more expensive" with "worse."

Just because they are more expensive doesn't make them worse, or mean they are lower quality.

I STATED IN MY FIRST POST THAT COST ISN'T A FACTOR IN MY SUGGESTION.

My point has been made clear. I stated why I prefer and suggest them, and the only thing you can do is argue they are unnecessary because of cost.

I'd like to know how something functional, something that provides a "service" is comparable to chrome accessories. Something that DOES something other than looks, by the way.

Yes, the stock head bolts do the job. They do it twice, if taken off.

Now, if you have taken the head off once, you've used 1/2 their recommended life. Bolt failure isn't the only reason a head must come off, and I've heard more than one person say they've taken theirs off a couple times.

That right there is the recommended life of your wonderful stock head bolts.

So before you go preaching to me about head bolt failure, think about the other things involved, other reasons for having to pull them out of a head more than twice. Because its happened before to users on this very forum.

And lastly, I'd like to apologise to you again for stating my preference to use better quality parts when I am able to budget for them.

Which is what started its **** storm involving a supporting vendor.

SeriousOffroad

First off, my vendor status has nothing to do with this discussion.

If you think that you need to plan for a removing your cylinder head shortly after installing it, by all means install studs if your so inclined.

One vital tidbit you didn't include in your recommendation was exactly how to install the head with 7" or so of threaded rod sticking up from the block. No way to get the head past the seam/lip in the fire wall. If the rig is lifted then removing the motor mounts and let the engine drop as low as possible, but even that might not be enough.

For the average guy repairing a leaky head gasket or replacing a cracked head, OEM style hardware is more than adequate.

If you are going to R&R a cylinder head time and time again...knock yourself out.

Gee oh Dee

You are correct, and I never disagreed with the fact that the OEM style bolts are more than adequate. Notice before any of our discussion started I even suggested that the information you included about the reuse of the original studs a second time was good to know. And I wasn't joking.

However I still say better equipment used isn't going to hurt anything at all if you can budget for it.

I consider myself average, matybe a bit above, although I've never rebuilt the top end of these 4.0s. I'm at a disadvantage from that standpoint, but I'm not new to wrenching alltogether. I'd still be more than happy using studs.

As for having to install the studs then drop the head on top, why not line the head up with the studs that aren't blocked by the firewall, then install the rears in the same fasion as a bolt? Again, I've never done a top end on these motors, but I see no reason that this would not work. Maybe you can help with that?

I am also still waiting to hear how the studs are bad, though. They provide better clamping on the head and are made of better quailty. Maybe its more difficult to install some of the studs, but I still don't see what my suggestion could hurt.