Cylinder Head Casting Number

[Stomper]

Ok, so I am trying to order a new engine for my 87 Eagle wagon. I have a couple options but the question about my cylinder head casting number keeps coming up. I was told to take off the valve cover to see it, but that seems like a bit of work just to get a number.. Is there any way to find this information in another manner? I put a magnet on the metal cover and it didn't grab so I know its aluminum but that's about all I can say right now.
Thanks,
Stomper

[mudkicker715]

87 with aluminum was 3661 on mine.

[NoCoEagle]

3661 on my '88. Although I'd advise highly against spending any decent amount of money on a replacement 115hp motor... the 3661 head was an awful design and a 7120 head from a 4.0 will basically bolt on. From there you get a Motorcraft carb conversion kit and do a hotter ignition upgrade, you've given yourself at least 150hp compared to the stock 115 and spent a LOT less.

Why are you ordering a whole engine? What's wrong with yours? If you're set on buying a turnkey engine then I suppose I can't stop you, but I wouldn't be caught dead spending any money at all rebuilding a stock 258. Cheaper to convert to a 258/4.0 hybrid and you'll make so much more power that way.

EDIT: Just food for thought, you can buy a new 115hp 258 motor that will be very easy to get working, or you can mix and match parts from a 4.2 and a 4.0 and make up to 180hp without spending any extra money, although the process is more involved. Unless, of course, you go through an experienced engine builder who wouldn't think twice about a 4.0 head and cam swap.

[standup650]

ya i just got a 93 Cherokee for $600 bucks. 4.0, ax15, NP231, d35 rear. lot of bang for the buck. and maybe a SAS front in the future.

[NoCoEagle]

Yup. If you want to go the drop-in-engine route, I'd see if you can find either a rebuilt (like you're looking at) 4.0 to drop in (with a little modification), or find a 258 short block and slap a reman 4.0 head on top of it, put a 4.0 cam and lifters in it, use your 258 intake, upgrade to motorcraft carb, upgrade to a hotter spark, maybe go serpentine belts... lots of options for less than an entire engine is going to cost. I don't know how destroyed your motor is, though. Anyway, ultimately you'll choose what will make you happiest. Myself, I look at price:performance, and the stock 258 is gonna be more expensive and make less power. But, if I put a turnkey 258 in my car, it'd be driving right now instead of sitting. So that's worth something.

[Stomper]

This is my everyday driver... My options are very limited at my current location for working on the car myself. My friend has a shop and willing to do drop in but not tryin to do a project.. As I said, I need this car back running ASAP and my thinking is a rebuilt engine with warranty gives me more years to enjoy the car.. Power not the problem for me. I need reliable. Wish I had place to work and time to do it but that's not the case. Every day without this car is a day I won't make it to work without a major hassle. Wish I could go fuel injected but the need of car outwieghs my wish list.
Stomper

[mudkicker715]

87 with aluminum was 3661 on mine.

i understand your problem/need. thats why i gave you the casting number i did.

i said nothong about my 2 strokers heads. 1 being  a 7120 the other a 2686.

[68AMXGOPAC]

I was thinking you were buying a long block and couldn't figure why the cylinder head number would matter ??

[Stomper]

Just want to say thank you for the number and the input everyone. Found a few 258s with low miles and looking into that right now. Eagle just left to shop on a tow truck... Update when done..
Stomper

[Canoe]

... find a 258 short block and slap a reman 4.0 head on top of it, put a 4.0 cam and lifters in it, use your 258 intake, upgrade to motorcraft carb, upgrade to a hotter spark,...

Which cam & lifters for this?
Any from a 4.0, or something special required?

[captspillane]

... find a 258 short block and slap a reman 4.0 head on top of it, put a 4.0 cam and lifters in it, use your 258 intake, upgrade to motorcraft carb, upgrade to a hotter spark,...

Which cam & lifters for this?
Any from a 4.0, or something special required?

You can use either 4.2 lifters and pushrods or 4.0 lifters and pushrods. You cannot mix and match. You cannot use 4.0 lifters with 4.2 pushrods. They're slightly different lengths individually but the same length put together. I guess the extra 1/16" of added length to the 4.0 lifters gives it a marginally higher output and I've been using those when I buy new ones. I doubt it makes that big of a difference unless you make the mortal mistake common to internet forums. I saw several places online where guys told you to keep the pushrods when you get your donor 4.0 head but leave your 4.2 camshaft and lifters alone. That wouldn't work.

The reason they say to use a 4.0 camshaft is that it has much more aggressive lobes exactly like a performance carb camshaft would have. The only difference I could tell visually from my stock 4.0 camshaft and my Crane carb cam was that the Crane had the mechanical fuel pump lobe and the 4.0 did not. Everything else looked exactly the same and drastically different than the stock 258 camshaft. The 258 lobes are really conservative. Ever wonder how AMC took a 115 HP 4.2 and made it reborn as a 190 HP 4.0 with less displacement but almost twice the power? The camshaft had a bigger effect than the MPI or even the better head design. It's much cheaper to buy a stock 4.0 camshaft and an electric fuel pump than it is to buy a performance aftermarket camshaft and you'll realistically not be able to tell the difference between the two once the engine is running. When a new aftermarket camshaft costs $300 (but have the lobe for a 258 mechanical fuel pump) most guys will buy a low mileage 4.0 camshaft from a junkyard for $20 and a low pressure electric fuel pump for $60. The mechanical fuel pump stays on the side of the 258 block to cover the hole but it won't work without the lobe underneath it. It's gets you almost exactly the same performance for a third the cost.

[carnuck]

4.0L cam has no lobe for the fuel pump. (aftermarket does, like the nice Crower cam I plan to go with)