LA vs Magnum

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green440duster

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I looking at building a 360 (in a Duster)for mostly street with capability to be well represented at the strip if need be. Looking for best bang for the buck with the goal being decent power but very reliable and streetable. I am just debating what engine to start with LA or 93-95 Magnum out of a truck? What does everyone think??
 
green440duster said:
I looking at building a 360 (in a Duster)for mostly street with capability to be well represented at the strip if need be. Looking for best bang for the buck with the goal being decent power but very reliable and streetable. I am just debating what engine to start with LA or 93-95 Magnum out of a truck? What does everyone think??
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I have been told by a machinist,racer,engine builder that has done this stuff for 30 years that Magnum heads are nothing but junk. Why.... I do not know but that is what the man said. He has one pile of Magnum heads sitting out in the wheater while all the LA stuff is covered up nicely. I've seen that with my own eyes. LOL I guess that dose not mean the 93-95 blocks are bad however.
 
It's a catch 22. Start with whatever you want. IF, you want to do a hybred mix of LA lower half and Magnum head it, that would be OK as well, but it is an extra expense that is not cheaply done.

I do like the Magnum head for it's as is performance. The MP create engine shows how well they are in a "As cast" form. Basicly a stock engine with a single plane M-1 intake and a cam with what MP sugests, a 750 carb and large tube headers making 380 HP. All the mags I have seen dyno this engine have all made over 400+ HP.
The roller cam of the Magnum engine is a plus. Can be drilled to oil like an LA.
 
Maybe because the mags tend to crack?

That was the reason I was most often given when looking through junkyards for a set.

But the EQ heads resolve this issue.

I would have asked why he thinks thier junk.
 
needsaresto said:
Maybe because the mags tend to crack?

That was the reason I was most often given when looking through junkyards for a set.

But the EQ heads resolve this issue.

I would have asked why he thinks thier junk.
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What is EQ heads?


I think he told me why but I was off in left field at the time. This fellow talks fast and I probably was recovering from what he had said earlier. LOL!
 
needsaresto,
Your right they do crack, the reason being that they are run very lean to manage emissions and the heads are made of harder supposably more durable material. I've only seen a handful that werent cracked.

Mullinax95,
Maybe it was because of the valve size and port volume for the size of the engine that they were going to be used on. I know I'm going to catch some flack here but they are too large for a 273 or 318 engine, and that they wanted to use one setup for both the 318 and the 360 engines. On the 360 engines they work great but the comprimise that they tried to do was use smaller valves so that they would work on both the 318 and the 360 engines. The problem that I see is the port volume is too large along with the valves for the 318. So in this case the 302/318 heads would be the better choice.
 
BJR, I think the reason Ma Mopar stayed with the small intake valves, even on the 360, is because the small valves keep the charge velocity up, so throttle response at low RPM is better. That (low-end throttle response) seems to be what their customers care about, mostly.

Having run 360s with both the 1.88" and the 2.02" intakes, I can tell you that the off-the-line performance of a 360 with big intakes is rather slow, especially in a heavy vehicle with a TorqueFlite, unless you use a high-stall converter. But that 360 with the big intakes really begins to crank once the RPMs (and therefore the charge velocity) build up a bit.
 
1 head for 2 engines is a problem that the factory has had to make a tuff choice on. In general, it has to save them tons of money doing it that way. With modern F.I. and computers, drivabilty doesn't suffer like it would once we get our hands on it. Bigger cams, upped compresion, (eeeek) carbs and such things that make a head/valve choice more critical.

Not giving out flak to anyone (LOL, BJR) but the magnum head is a better choice than a standard 1.88 letter head and certainly over a 2.02 on a 318.
 
Hey Jamie,

There are a few things to think about in this.

1. age of block - just because they are cast iron doesn't mean they last forever. Lifter bores can get sloppy along with just palin metal fatigue.

2. how much power do you want - with magnum heads you can be limited in the amount of lift by the spring seats. more machining costs.

3. compression - with the magnum heads being closed chamber you can run a little more compression than with open chamber heads. I have 10.58:1 and can run 89 octane no problem.

If it was me, I would go with the newer block if for no other reason than it is already setup to run a roller cam.

Jack
 
eq heads are the clearwater cylinder head casting. They make their own 360 magnum head that is thicker and with better flow than the originals. Just put mine in two weeks ago and they run great.
 
They cast there own Magnum heads without problems from Chrysler?
 
I'm wondering, how much would it cost to fit Magnum heads to an LA block? Will it really be over a thousand bucks?
 
Besides the cost of the heads, intake and gaskets?

Proper length pushrods and AMC lifters.
MoPar has the pushrods, though I read somewhere there a teeny tad long for the application. Theres alot of grey area in that statement.......
 
Mope, that price is about right. It all depends on what you go with. Mine was closer to 1200.00 since I went with eq heads and eddie air gap intake. throw in gaskets, pushrods, new water inlet, and your there.
 
Hmm,$1000?

Really?

I bought a remachined and ready to go pair of heads,$530 taxes included.I did get lucky here finding a pair that had no cracks.BUT,later year magnums are less prone to cracks.
The M1 intake I got used from ebay for $105,plus $20 shipping.
Porting templates cost $10,$3 shipping.
Head bolts,$55 from the local dealer.
Pushrods cost about the same.
Used magnum valve covers for $15 off ebay.Shipping was about $10.

Thats less than $750.

Cant see gaskets costing $250 bucks..

I guess it pays to be patient and shop around!
 
I think all the EQ magnum heads are made in New Zeland. They have thickend area between the valves to fix the Chrysler head craking problem. They also have thickend decks, and they have better flow than a Mopar RT head. They also have a higher nickel content that makes them harder. And they are brand new. Why use junkyard heads that arn't cracked now but might be next year, after you sank a bunch of money in them.
I used them on my 340 and had them milled down to a 57cc chamber. The machinest said they were harder to mill because of the nickel content,than a BBC race head.
 
needsaresto, good price shopping on parts. It beats brand new everything. But thats where the difference comes in. Theres surley more expensive ways to do it Heck, you could start with brand spankin new Edelbrock castings. LOL!

I have read somewhere, probably here, that the MP Magnum porting templates are discontinued. Any truth to this?
If so, could I borrow those templates to copy?
 
I have the Mopar Performance R/T iron heads and love them. I bought mine for $580.00 shipped brand spanking new on eBay. One head was assembled, one was bare.



bobscuda67 said:
They also have thickend decks, and they have better flow than a Mopar RT head.
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Do you have direct back to back comparison flow bench numbers to prove this? I heard they flow almost as well as the MP R/T heads. Shady Dell says the R/T have the best valve job they have ever seen on a production/aftermarket head.

I also have two sets of factory production heads that will be going on small blocks in the future.
 
rumblefish360 said:
needsaresto, good price shopping on parts. It beats brand new everything. But thats where the difference comes in. Theres surley more expensive ways to do it Heck, you could start with brand spankin new Edelbrock castings. LOL!

I have read somewhere, probably here, that the MP Magnum porting templates are discontinued. Any truth to this?
If so, could I borrow those templates to copy?
Click to expand...

That's what I was thinking yesterday about the Eddies. Eddies that are ready to run will cost about $1200-1300.
 
Hey, good mornin mullinax;

It wouldn't be a bad way to do it all from scratch, but a tad pricey. The pay off would be new aluminum decent flowing heads. And of course, if on top of a LA block, the added lift at the cam is nice.

If one could clean them up and add a touch of work to them without added machinest costs, it starts looking really good.
 
Morning rumblefish,

I believe the only draw back about the Eddies is the 2.02 valve size is to large for most stockish/performance type motors far as keeping the velocity up. If they have smaller valve type heads I have never seen them.
 
He he he, maybe, but thats not a problem in this stable. He he he. I'll put the screws to it. Promise.
 
Another vote here for the newer magnum engine. As someone said earlier there's less chance of worn out lifter bores than the earlier blocks that have a ton of miles on them. I have a nice 360 block/coffee table that has this problem. Seems the lifter bores were worn before the cyl. walls. Cylinder walls cleaned up at .030 over but the lifter bores are very sloppy. I'm sure there is plenty of good older blocks out there but make sure and check every clearance good before you sink allot of money in it. I didn't and it came back to bite me.
 
daniel_depetro said:
I have the Mopar Performance R/T iron heads and love them. I bought mine for $580.00 shipped brand spanking new on eBay. One head was assembled, one was bare.






Do you have direct back to back comparison flow bench numbers to prove this? I heard they flow almost as well as the MP R/T heads. Shady Dell says the R/T have the best valve job they have ever seen on a production/aftermarket head.

I also have two sets of factory production heads that will be going on small blocks in the future.
Click to expand...

I got that information from the Hughes engine website. If you look up the iron ram head they have the flow numbers listed.
 
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