Whats years are best for LA 360's

-
Ol'forest

Ol'forest

Well-Known Member
Joined
Apr 6, 2009
Messages
419
Reaction score
78
Location
Hamilton, New Zealand
Looking around at good running second hand 360's and wondering, if the later roller cam ones are okay to start with, or what you guys recommend, I'm looking to do a very budget build, so the less mods the better. Are the later heads (pre-magnum)good? What should I start with?
 
As far as pre-Magnum 360 blocks go, many believed that the first few years of production were the best (early 70's). I've also heard up to 74-75 was good as well. If it's not gong to be something crazy in the HP/torque dept, you can get away with almost any of them. For a budget build, you could use a pair of OEM X, J, O heads (especially if you can find a set already rebuilt). You can also go with an aftermarket head that is not too expensive (RHS or the Indy replacement heads, etc.). There's a few choices out there. All depends on your desired end result and your budget. GL.
 
In my opinion all the 340/360 heads are the same(in the 1.88 intake valve size) now the non mag 308 are claimed to be a slight bit better, head. Mag's all i know about then is that they crack, but sometime will run for a long time that way.

Blocks?????? early ones are said to have a little bit more metal around the cyl walls. Every thing i have said can and will be argued:poke::D
 
Cudafever said:
In my opinion all the 340/360 heads are the same(in the 1.88 intake valve size) now the non mag 308 are claimed to be a slight bit better, head. Mag's all i know about then is that they crack, but sometime will run for a long time that way.

Blocks?????? early ones are said to have a little bit more metal around the cyl walls. Every thing i have said can and will be argued:poke::D
Click to expand...


No arguments here but just a mention that out of the 1.88 intake castings, some are a little more highly sought after than the others (with the J being the least from the above list which also shoud includes the U). Can't comment on the 308s ... never used 'em.
 
All ironheads crack sooner or later and 99% of the time, you'll never know there cracked. Thats the bottom line. OH! And a fact.

The best 360 is the one that sonic checks good. But since your on a less than Road Kill budget....

The Magnum headed 5.9 (AKA - 360) is a excellent unit to start with. The F.I. set up Chrysler uses normally shows almost no wear worthy of print in the cylinder bores. Lower the mileage the better of course. I took a '00 5.9 and opened it up to find cross hatch marks with 75,000 on the clock.

Magnum engine draw backs?

Different external balance than the 360. No mechanical fuel pump boss. Can not use "LA" heads so quickly. Limited Magnum intake selection. (But the current offerings are excellent and probably won't leave you wanting for power since between the MP M-1 single plane and the Edelbrock RPM, it pretty much covers all the bases except blinding fast and ultra frugal.) But all of that can be changed with money.
I used a B&M flex plate to mate to my early 70's 727. The stock Magnum 5.9 should be purchased with the flex plate. It is what you want and need.

Pre Magnum 360's are also excellent choices since there also a roller cam engine like a Magnum. Draw back; Older engines tend to have higher miles. Earlier F.I. engines are also very good on the wear factor, but, the early F.I. may not be so good to the engine like the more modern one is. Most V8's of this error/series were used in vans & trucks.

Early "LA"n While probably the best interim of cheap parts, these do require some attention that may cost. IF you canget a low mileage rebuilt engine out of a project car forgotten about or no longer wanted, these would be just fine for a multitude of power levels and duties.

No matter the engine series selected, the heads ability of which you show concern about is addressed best with 2 items to help out and the power of the engine along. Headers (With free flowing exhaust) and a proper camshaft!
 
Ex truck 360's are the most common down here, and most likely to find in good low mileage condition, just I'm not familiar with those roller cam FI engines. Basically looking for now to get a cheap lowest mileage 360, and chuck a 4 barrel, intake and mechanical fuel pump and use it till I get around to hopping it up. I'm assuming no provision for mech fuel pump on the roller cam motors?
 
LA ?? pretty much any are good. I would say the roller cam ones with 308's would be an excellent choice. I mean, if you don't have to use zinc additive with your oil (or buy expensive oil), that would be cheaper, right? I've used 308 heads, and I liked them. I have a set of 308's right now I'll use on something sometime. I had a '89 360 and it came with the fuel pump eccentric on the cam, even though it was TBI. But, I'd buy the best running 360 I found for a low price and not worry about any of it. If you get a truck motor, you'll be pulling the oil pan/oil pickup tube for a car one if it's going in a car.
 
Thats what I'm thinking too, not worried about performance too much to start with, but just something that runs okay around town with my 4.11 rear.
 
The early F.I. Engines have the timing cover with the fuel pump boss. I don't know when they stopped there use. Even more so for out of country vehicles. There's minor differences between the USA, Mexico & Canada. LOL, were all boarder buddies! Ha ha ha ha.

I agree, any LA is what I myself would look for. And if you find a roller cammed 360, all the better. If not, there's several lines of solid cams that are stout and able to make serious power. Anroller cam is not mandatory for power.
 
Any year, one that you can hear and see run. Spend more initially for a verifiable good one. Then add the bolt-ons. Easy formula for fun.
 
I prefer magnum blocks. You get a factory roller setup. If you do some digging you can find some that have LA head oiling provisions from the factory. I have heard some claim that early LA blocks have more meat in them but I've also seen multiple engine shops provide sonic checked data that says none are thicker than the other. However, magnum blocks are a lot less susceptible to core shift. This can be more important if you're trying to build with precision.
 
Just curious, not to derale the thread but did the blocks all of a sudden get way better (consistent) with the Magnum update, or was it more of a gradual thing that also affected the later LA engines as well?
 
GTXperience said:
As far as pre-Magnum 360 blocks go, many believed that the first few years of production were the best (early 70's). I've also heard up to 74-75 was good as well. If it's not gong to be something crazy in the HP/torque dept, you can get away with almost any of them. For a budget build, you could use a pair of OEM X, J, O heads (especially if you can find a set already rebuilt). You can also go with an aftermarket head that is not too expensive (RHS or the Indy replacement heads, etc.). There's a few choices out there. All depends on your desired end result and your budget. GL.
Click to expand...

Btw: My comments above are not in comparison with the Magnum motors because I don't have much hands on knowledge of them when it comes to performance use. My opinions are based off of pre-Magnum 360s. Everything's up for discussion & interpretation right?
 
MOPEkidD-3 said:
Just curious, not to derale the thread but did the blocks all of a sudden get way better (consistent) with the Magnum update, or was it more of a gradual thing that also affected the later LA engines as well?
Click to expand...
Just my opinion but the LA mold were old and old tech, mags got a new mold(less wear and better tech(design/ideas) to help with core shift..........don't mean it still wont/don't happen.
 
Cudafever said:
Just my opinion but the LA mold were old and old tech, mags got a new mold(less wear and better tech(design/ideas) to help with core shift..........don't mean it still wont/don't happen.
Click to expand...

Gotcha that's what I wanted to know... so they basically re-tooled to make the Magnums is what you're saying right?
 
Hmm well first i'm taking out my arrrs as i have no idea BUT i bet some of the old tooling went into the new mag block...............
 
Based on my own testing experience the 80s LA 360s are much more consistent, and the Magnums are just as good, albeit a little thinner all around.
 
You must log in or register to reply here.
-

Back
Top