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Debate. LA 360, or 5.9 Magnum?

Triplegreen500

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So, I have one of each. This is for my 72 Satellite wagon.

Current motor in the car is a mild LA 360, unknown specs. Dual plane, manifolds not headers, no crazy cam, iron heads but I'd have to check for casting numbers. Runs....meh. I could build this up.

Or, I have a (admittedly high mileage) 5.9 Magnum in a 99 Durango. Bone stock.

Back in the day, I ran the wagon on an MP 360/380 crate motor and loved it. Single plane, .288/.292,
.513 lift cam, good heads...that thing SCREAMED.

I want the wagon to go fast again. Dollar for dollar, would you build the LA? Or the Magnum? Street car, sleeper...just wanna have fun with it again.

And maybe a procharger down the road....hehe....
 
The magnum is better in stock form.
I imagine you can do either.
 
I’d side with the Magnum. There are two/three possible disadvantages to it.

The shorter deck height may possibly be a minor problem with lower compression pistons for boost. Or at least a reduction n multiple choices.

If you move away from the stock cylinder head….
The lack of head oiling via the block into the head is t a deal breaker but now requires you to use pushrod oiling for the head. The best head designed for the Magnum block is the Edelbrock head and another cylinder head use will require for thought on rocker arms.

Also staying with a Magnum head has limited intake manifolds for it. While a Edelbrock RPM will cover much, the only other intakes I can think of made new are the Indy single plane and the chink knock off.

While these are not big issues, it’s a thing to look out for.

The pro of the Magnum is I’d bet the cylinders are in very good shape since the OEM F.I. system is very good.
The block is set up for a roller cam and the use of the OEM Hyd roller lifters and pushrods save a lot of money for an easy upgrade to a better camshaft.

IF you move to a solid roller cam, the additional lifters needed are pricey but worth it. You won’t need the slider to hold down the lifter retainers (bow ties/dog bones)

Again, with all of that said, between the two, I’d do the Magnum block.
 
I’d side with the Magnum. There are two/three possible disadvantages to it.

The shorter deck height may possibly be a minor problem with lower compression pistons for boost. Or at least a reduction n multiple choices.

If you move away from the stock cylinder head….
The lack of head oiling via the block into the head is t a deal breaker but now requires you to use pushrod oiling for the head. The best head designed for the Magnum block is the Edelbrock head and another cylinder head use will require for thought on rocker arms.

Also staying with a Magnum head has limited intake manifolds for it. While a Edelbrock RPM will cover much, the only other intakes I can think of made new are the Indy single plane and the chink knock off.

While these are not big issues, it’s a thing to look out for.

The pro of the Magnum is I’d bet the cylinders are in very good shape since the OEM F.I. system is very good.
The block is set up for a roller cam and the use of the OEM Hyd roller lifters and pushrods save a lot of money for an easy upgrade to a better camshaft.

IF you move to a solid roller cam, the additional lifters needed are pricey but worth it. You won’t need the slider to hold down the lifter retainers (bow ties/dog bones)

Again, with all of that said, between the two, I’d do the Magnum block.
And with the Magnum you can run whatever oil you want. No high zddp oil needed with that roller cam.
 
What about engine mounts? Just wondering if there is a difference in the two?
 
If I recall, the Magnum crate motor dropped right into my 318 wagon back in the day.

Of course, it ripped them apart in short order.... :thumbsup:

Good info, all. Thank you! It's about time I get this party started...I figure, the car is sitting on stands in the garage...it can sit there just as well with the engine bay empty and me working on a new motor and trans in my spare time....
 
So, I have one of each. This is for my 72 Satellite wagon.

Current motor in the car is a mild LA 360, unknown specs. Dual plane, manifolds not headers, no crazy cam, iron heads but I'd have to check for casting numbers. Runs....meh. I could build this up.

Or, I have a (admittedly high mileage) 5.9 Magnum in a 99 Durango. Bone stock.

Back in the day, I ran the wagon on an MP 360/380 crate motor and loved it. Single plane, .288/.292,
.513 lift cam, good heads...that thing SCREAMED.

I want the wagon to go fast again. Dollar for dollar, would you build the LA? Or the Magnum? Street car, sleeper...just wanna have fun with it again.

And maybe a procharger down the road....hehe....
Because your wagon is a bit heavy, a Stroker would work well for it. You can stroke LA's and Magnums quite easily and they make a lot of torque. You don't need a huge cam and crazy gears to make them work.
 
The wagon ran low 13s back in the day with the crate motor, a reverse/manual 727, 2400 stall, and the factory 3.23 SG rear. All the weight is in the right place - behind the axle. Weight transfer ROCKS. 1.60 60' times all day long on street tires :thumbsup:
 
What are you calling "high mileage"?

At 177,000 mine runs like the day I bought it with 31,000 on it's clock.

Moves my 4200 pound truck like a scalded dog with the 3.92 SG 9 1/4 and 9" wide tires.
 
I want to say mid-high 200s...but I'd have to check. It's only off the road due to rust. Highly unsafe. Replaced with a $2500 2008 5.7 Durango.
 
Is there a difference in the R/T profile?
Asking for a friend.
Now that I don't know. Oregon can regrind the stock cams to increase performance a bit. I haven't heard how far they can go though.
 
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Around here, you can get a 150,000 mile 5.9 in a truck with a bad trans for $2500 or less.

I've seen them as low as $800.
 
I have both already.

Just debating which one I want to build.

I also have an '05 5.7 with 36k on it, from my totalled (one-owner) Magnum R/T that I could build. It's been indoors since the car was totalled in '08. But that entails massive accessory changes like power steering, front end drive kits...wiring and computers if I keep the efi...but I still may do it.

It's just time to get moving on this car before I'm too damned old to do it!
 
The Magnum benefits; you can use the factory roller lifters, stock heads are better, rockers are cheaper. LA benefits, shaft rockers are stiffer. Note that the mounts are the same. The balance between the 2 is different. So you'll need the correct flex plate or weighted converter. We have two boosted LA street motors. A turbo 360, 9.5-1, with ported Eddy heads, .550 hyd roller, blow thru on E85, 3775lbs. And a 340 with a roots, 8.0-1, ported factory heads, .550" solid flat tappet, 3875lbs, The turbo car at 14 psi will go in the 9's. at 22psi it's been 9.55@142. At 12 psi the blower car has been 11.0@122. Both in street trim thru the mufflers using sticky tires.
Doug
 
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