Modern 360 question

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19dart71

19dart71

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This may sound like a stupid question to some of you pros, but I am just starting out and learning the ropes so please don't get offended by my ignorance.

Last year a I read an article on putting modern magnum heads on an LA 318. I thought it over and purchased some with the intent of rebuilding my 318. I have since decided to have fun driving my 318 while I patiently rebuild a 360 as a replacement. My question is this. If the magnum heads will bolt onto my old block (or a 360 for that matter), would I run into problems or complications if I decided to find a complete modern 360 to rebuild. Also, (this is probably the stupidest question of all) what is the real difference between a long block and short block? Are they really that different? I am assuming that my 71 Dart has a short block. Am I right? Also will the modern 360s link up with the 904 or would I be looking at replacing the tranny as well? Thanks for any knowledge you are willing to lend.
 
short block is block with pistons..crank ..rods and cam...

long block is short block with heads and intake..

new modern 360 is same as old 360 except for the heads...rockers....and how they oil thru pushrods.....

you can put an intake and regular distributor in modern 360 to run in your dart...
 
70aarcuda said:
you can put an intake and regular distributor in modern 360 to run in your dart...
Click to expand...

It should be clarified that the modern (magnum) 360s have a different intake bolt pattern than the older 360s. However you can redrill them to fit correctly. There are carb'd intakes that are made specifically for the modern 360s as another option
 
The modern 360 has a roller cam but is set up for torq, as it is used in pickup trucks. They stop making power at about 5500rpm. Most of the cams you find for the modern 360 are designed for truck engines w/ efi. So you have to do your homework if you want to build one that will turn the rpms like the older 360s. (I went w/ a big hydralic roller and am not real happy with it.) Also the modern 360 is internaly balanced, older 360 externaly balanced. You can use the 904 but you will need a torqconverter for an internaly balanced motor. I used one from a slant 6. Not sure if the 318s are internal or external balance. GOOD LUCK!!
 
modern or magnum 360 is still external balanced just uses less weight then the LA 360........
 
The modern 360 is externally balanced too. It does however have a different balance factor so old 360 balancers, flex plates, convertors don't work.
 
To clarify:

5.9 Magnums ("modern 360") are externally balanced. The balance is NOT the same as a previous 360. It requires a specific Magnum balance balancer and flexplate.

All the LA front cover and such will bolt to a Magnum engine. LA style transmissions will bolt right up also.

If you use a Magnum flexplate, you need an internal balance converter with no weights.

These motors will turn significantly higher than 5500 with a good cam and proper valve springs. I ordered a custom camshaft from Comp and mine makes power to 6700.

Steve
 
I'm confused now. Buy externaly balanced I mean there is a balance weight on the converter that is used to balance the engine. The magnum, as LXguy stated uses a converter w/ no weights on it.(internal balace) The thing to keep in mind is not to just slap on a converter and flexplate from an LA 360 on the magnum.
 
externally balanced means...that the damper/balancer is not nuetral balance...it has weight offsetted..

also...weight must be on either the converter or the flexplate but not both....

why are 360s externally balanced?????

the crankshafted are casted...not forged...the cast crank the metal is not as dense and there for does not weight as much as a forged cranks

went balancing the 360 engine the counter balances are not heavy enough to balance to the weight of the rods/pistons...

or to internally balance a cast crank ...marolley metal which is really dense is added to the counter balance on the crank...a hole is drilled and mallory metal slugs pressed in...

i spend about 400 bucks last year internally balancing a 360 crank...mallory metal....

....
 
It's a little confusing. Short block/long block discussion has no bearing on the distance from the front to the rear of the block, but rather the degree of completion.

IME a short block is the assembled block, crank, rods, pistons, rings, pins, bearings, timing chain, and cam. A long block assembly adds fully assembled heads and valve train, harmonic balancer, front cover, oil pump, & oil pan.

When you get to the size of the block, the big block/small block discussion begins. The 360 is a small block from the LA engine family. Family members begin with the '64 - 69 273, 67 & on 318, 68 - 73 340, and the 71 & on 360. The LA engine block has been stroked out to 408 CID routinely, with some going even farther.

The Mopar big blocks with wedge type combustion chambers are referred to as the B/RB motors. The block design dates back to the late 50s. The B motor came in 350, 361, 383, and 400 CID configurations. The RB is essentially the same engine with a greater deck height that allows for longer strokes. The RB came in 383, 413, 426, and 440 CID. Of these the 383 B and the 440 RB were optional in A-bodies. The 383 from 67-69 and the 440 was a 69 only install.

The 426 Hemi was installed in a few A-bodies in 68 intended for competition. It is sufficiently different to warrant a separate discussion.
 
So from what I can tell, would I be better suited (with beginner level experience) getting an older, vintage 360 and putting the magnum heads on it as I had considered doing with the 318? I know there will be a special intake and push rods that allow oil to pass through (and a few other small modifications). Would a vintage 360 be an easier rebuild and install for a novice? With the vintage motors I can still use the older LA flexplates and balancer? Would I need a different converter than what my 318 uses? If so, any recommendations?
 
19dart71 said:
So from what I can tell, would I be better suited (with beginner level experience) getting an older, vintage 360 and putting the magnum heads on it as I had considered doing with the 318?
Click to expand...

Not really. The only real difference parts wise is going to be the valve gear. The lifters, pushrods, and the difference between pedestal and rail mounted rockers. The later vintage 318/360 uses a roller cam like the Magnum does.

Most vintage engines use a flat tappet. The AMC V-8 lifter can be used with tubular pushrods to provide lubrication to the top end of Magnum heads.

I know there will be a special intake and push rods that allow oil to pass through (and a few other small modifications). Would a vintage 360 be an easier rebuild and install for a novice?
Click to expand...

I don't think the older LA is going to be any more difficult than the Magnum. Aftermarket support of the Magnum is going to be less than the "vintage" engine.

With the vintage motors I can still use the older LA flexplates and balancer? Would I need a different converter than what my 318 uses?
Click to expand...

The older 318 is internally balanced. The 360, vintage or Magnum, is externally balanced under normal circumstances. So yes, a different converter is required.

If so, any recommendations.
Click to expand...

TCI or B&M make converters for the 360, assuming you can't use the one that is already on the engine
 
Thanks to all for the info. FABO is great!!
 
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