Best 360

HectorVenezula

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I'm looking for a 360 for my fifth Avenue what would you recommend I found an early 70s out of a truck late 70s out of an rv and an early 80s out of a truck
 

80mirada

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71-74 blocks have "thick"cylinder walls, since they shared cooling jacket cores with 340s. That said, it really comes down to maintenance, and mileage. You want to see good clean coolant, and oil with no obvious problems in the engine you choose. If the engines are still in the vehicles, look at the radiator and hoses, they can show signs of over heating or leaks. You don't want an engine that was overheated a lot, or has a rusted out coming jacket
 

Aspen500

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If you're not aware of it, you'll need a car oil pan and pick up tube. The truck pan has the sump in the same place as the steering linkage wants to be. I'm with 80 mirada, go with the early '70's engine if possible. The later ones are fine too but with thinner cylinder walls, core shift becomes a concern, especially if you're going to bore it out, and late '70's/early '80's quality control was,,,,,,well,,,,,,,,we'll just say it was lacking.:eek:
 

Davesmopar

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If the seller does not object, I would pull both valve covers to see how clean or nasty it is under them. Also I like pull the dipstick and check the entire stick not just the bottom but I make sure the entire stick is fairly clean or if it has like a black varnish on it, if it has a black type varnish on it than means are probably not changing the oil..

Also at least turn the engine over a few times make sure there's no binding or noise obviously, if possible do compression check... famous Benjamins on the ground you can crank it over by hand and get some compression, if all the pretty even except for one and you know I got a bad cylinder. Just a couple of thoughts......
 

Davesmopar

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The best 360; is the one you build with high compression pistons, modern closed chamber heads, a free-flowing exhaust ,and not stuck with a 2.45 gear ratio.
Hey, that sounds like a Magnum.....


100% true.... but you have to start with a block (used engine) unless going new aftermarket..... lol ;)
 

Duke5A

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Magnum motor, don't even screw around with LA. What's the plan for the car? Sticking to a relatively factory short block?

The thicker cylinder walls of the 70's stuff doesn't matter in the grand scheme. You shouldn't be boring a factory block anyhow with the primary intention of increasing the displacement - just enough to clean it up. My first 360 build was based off of a 1985 block and cleaned up fine a .040" with enough cylinder wall left.

Magnum motors offer a way better starting off point if what you're building is a semi-stock street cruiser. 400 HP is pretty easy to get with a 5.9L using factory heads and bottom end. They're typically in far better shape internally too due to being fuel injected.
 

Oldiron440

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No I'm saying the best 360 is a 440 or 400 stroked. Sorry I can't resist.
 

Davesmopar

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Yeah I was wondering what block you were going to use..... lmao (was trying to wrap my head around it and it didn't make sense)....

I like a stroker 400...... more ci less weight... My buddy is a Big Block kinda man and I am a small block kinda man....
 

Oldiron440

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The big block is a dinosaur from the fifties but is my connection with mopar.
 

ch1ll

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71-74 blocks have "thick"cylinder walls, since they shared cooling jacket cores with 340s. That said, it really comes down to maintenance, and mileage. You want to see good clean coolant, and oil with no obvious problems in the engine you choose. If the engines are still in the vehicles, look at the radiator and hoses, they can show signs of over heating or leaks. You don't want an engine that was overheated a lot, or has a rusted out coming jacket

I'm not convinced that any blocks past 72 have 340 cooling jacket cores. all blocks need to be sonic checked for core shift and overall thickness. and yes it does matter. thick stable walls make for good ring sealing at high compression ratios. I'm not sold on the magnum motors either, rocker arm studs suck plain and simple, cheap ass stupid GM idea.

as for thick wall, 72 and earlier 318's have the "340" walls as well as a smaller main bearing diameter which has less bearing speed because of less surface area = less friction. 318's are abundant and relatively cheap.

any way I would go with the block you have that checked out the best.
 

XfbodyX

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I find this interesting, the op didnt state weather he had expectations of a drop in and run deal or a rebuild.

I would like to ask the people who replied, when was the last time is they had a boring bar in a block or honed with a real hine in a fixture, a older la block then honed a pre mag block and can post what block seemed the hardest to machine as in the characteristics of the cast iron in particular blocks. How many here have personally had a fresh build constantly overheat due to a thin cylinder wall?

I think some are overlooking the op is simply looking to put a mild 360 in his 5th ave and if thats the case if the motor he buys currently runs it will survive a simple rebuild with a slight bore/hone.

Currently to many builders, a early 360 block with a known history either a early 70-s or a pre mag 360 they made for a few years is preferred if pushing the limits.

Most every reply posted here can be found through a search engine. Sonic checking is good to an extent, but how many of us rebuilt motors in the 80-s and never had a single issue?

The internet has really hurt and complicated the hobby more then its helped imo, before the internet people made a plan, asked a friend what there successful hands on combo was and grabbed the paw order form and had good running combos without doubts or indecision.

If it were me, id go talk to the people at the machine shop you plan to use and ask what they prefer to use and the positive and negative aspects of your idea since they see them day in day out.
 

Oldiron440

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You look at all the engine builders that bored everything .040, everything it's the only size pistons they bought.
 

BudW

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Note: I concur with XfbodyX’s comments, above.

I have worked with many a 340, 360 and even more 318’s. I hadn’t seen or heard anything about the early 360’s having thicker cylinder walls. Not saying it’s not true – I just hadn’t seen any differences nor heard anything saying otherwise. It is not worth getting into an argument about, especially if I have zip, zero, nada facts or documentation to prove either way.

I have “heard” the ‘66 and older “Poly” 318’s have really thick cylinder walls (maybe the thickest of all A/LA’s) and can overbore by huge amounts – but the lifter bore holes are not in same area so one would have make a custom camshaft to make one work.


An early (’71-73) 360 will run just as well as a 340 will, if you install better compression pistons, bump the valves up to 2.02”, add a stock 340 camshaft (or better) and 4-bbl intake.


My thoughts:
I also recommend keeping your existing 318 running – until you get your “other” engine built so car has a minimal amount of down time. The more down time usually means the less you want to finish your project.

Find a used 360 magnum engine, using tips mentioned above. You will end up with a nice running engine with the least amount of money put into it. Many things from your existing 318 will fit and work, but some things won’t.
A used 318 Magnum engine has a few less cubic inches and few less HP than 360 Magnum, but still a strong running engine in stock form.

Finding a used 360 pre-magnum engine is a close second. Again, many things from your existing 318 will fit, but some won’t (a little less than what a Magnum will need).

A lot can be done to a 318 (LA or Magnum), as well. Just need to keep compression and other things so it will all work together (instead of having parts fight against each other).

A stroker kit is nice for the extra cubes (and compression) – but those kits also cost more $$$.


I had struggled with this “thought process” after I got my Fifth Ave. The first thing I thought of was building up the 318. A short time later, was getting a 360 and maybe building it up. A bit later I was going with a built 340 (all Chrysler 340’s are High Performance, but the ’72-73 were more ho-hum because of lack of compression, IMO). I might have access to more Chrysler parts than many members have (possibly) and even had a 340 block in my garage at the time (not now), until I decided against that route.

I do have a nice low mileage ’79 360 Motor Home block and a good ‘85(?) 360 pickup block (not a roller lifter block). I even have a ’84 318 police engine as well. All three I have no current plans for – but NV is a bit of a drive to Oklahoma

What it came down to was what I wanted to do. Getting a stroker kit for a 360 and having over 400 cubic engine is great. What I finally decided was to get a big engine bigger so it wouldn’t work that hard, than to make a smaller engine work hard (if that makes any sense). Also I wanted my smile to get close to my ears (when wanted/needed) and going big the only option.

I have two 400 (NOS) big blocks (short blocks), stroker kits, aluminum heads and so forth already in my garage (it is getting a bit crowed in there, sense I also have a 440 Motor Home engine and the ’70 “U” E86 code 440 (out of my 300-H) in there as well as a half dozen transmissions).
20190919_181744r.jpg


Going big block is a whole lot harder than going 360 – sense there is a LOT MORE that needs changing/modifying.


I would recommend finding a machine shop in your area - sense they will be doing a lot of your work. One who has worked on Mopar engines is a huge plus. They might even have a source for a block (or engine) for you, maybe.

We can toss around ideas to you all day long – but this is your project and you have the final say.
BudW
 

Oldiron440

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I read the first two years of the 360 had the 318/340 water jacket in that you could use a 40 over 340 piston in a 360. I'll look it might be in the mopar engine book.
 
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