"I believe the 5.2 and the 5.9 Magnum motors have the same stroke)." Maybe the 340?

Are you referring to the LA 340 Magnum performance motor that was removed from production nearly 20 years before the Magnum series motors ever reached production?

The LA series motors and the Magnum series motors are considered different motors, much like the "A" motor and the "LA" motor.

The LA 318 and the LA 340 had always had the same stroke, but the LA 360 had a smaller bore then an LA 340 and a longer stroke then both the LA 318 and the LA 340. The LA 340 Magnum was designated as a performance LA small block Performance motor of Chrysler in the late 60s and early 70s and were called Magnum motors to differentiate them from the standard production work horse motors, the LA 340 Magnum being the only small block motor along with the big block performance motors, the 383 Magnum, and the 440 Magnum and has nothing to do with the Magnum motor series other then sharing a name.

The Magnum motor series was a new motor design that started production in the early 1990s. The Magnum motor series started with a 5.2, then added a 5.9, then called everything designed after the LA series motors magnums, including the second rendition of the 3.9 and 4.7 Magnum and a slug of V 6 motors also refereed tom as Magnum motor series motors. A 340 Ci displacement Magnum series motor was never produced.

You are losing me here, a 5.9 is a 360in size motor and has a different stroke than a 318 or a 340, magnum is irrelevant in this context.

Yup
.

You are both wrong!

The topic on hand here is a "2000 360".

If the model year is correct, by Mopar terms, that is a 5.9 Magnum motor. It has different valve covers and that beer barrel intake manifold and different exhaust manifolds. It looks different because it IS different. Both the 5.2 magnum and the 5.9 magnum have the same stroke length of 3.31 inches or 84.1 MM. The differences in the CI displacement is just the bore diameter.

We are not talking about an LA motor. The LA 360 went away in the late 1980s I believe. The magnum motors started in the mid 1990s and are a different series of motors. They are not the same motors, its just the displacement is close to each other. Until you understand that, you will never understand the conversion issues.

The 5.2 Magnum has a neutral balanced crankshaft. The 5.9 Magnum has an off set balanced crankshaft and needs the proper balanced flywheel. Both flywheels for the magnum motor series are available at Rock Auto. Buy the flywheel for the motor you have. The of set balanced 5.9 Magnum motor flywheel is not the same off set balanced flywheel the LA 360 uses. The two do NOT interchange.

Sorry Poorboy. 5.9 Magnum stroke is 3.58.

Same as the LA 360.

There's much more similarity between the LA and Magnum engines than you think and one can be converted into the other.

The difference in balance weight between the 360 and 5.9 is, I believe, due to lighter pistons in the 5.9.

Yes, so much confusion here. 273,318,340, 5.2 which is the same as the 318 are same stroke. 5.9 same as the 360 cu in. has same stroke. ‘Magnum’ was a Dodge monicker in 60s 70s. When the head-intake was changed in 92 with the 5.2- 318, it was then called a ‘Magnum’ engine. Small blocks only came with two strokes 3.31 and 3.58. All 360-5.9 had 4” bores, 273 had 3.63, 318-5.2, had 3.91, 340 had 4.40 bore. The reason 360s are external balance is because the pistons were shorter and lighter (all rods same length). My advice is to purchase the Mopar Engines book, it will explain it all, also get the Magnum engine book. No more bad info floating around the net.
I’ll add, the La 318 stopped in 91. La 360 92, then both became the new Magnums with new heads and the beer keg intake, side note the 5.2 and 5.9 share the same large main bearings, ask me how I know.

I'm getting ready to start building a 360 stroker motor with a new Mopar premium cast crank that I had offset ground down to SB Chevy small rod journal size to increase the stroke long before we could buy new stroker cranks like now.
I don't remember the exact stroke increase, I think it was near .125 increase, I will measure it before ordering pistons. I will have it internally balanced also
It will be going in a 1965 Valiant Signet with direct port EFI and a small single turbo on E85, I want to learn EFI tuning on boosted motors with this street car. I'm going to try and limit the boost to under 7.0 lbs. and shooting for 600 HP or less

I was wrong, carry on.

That I know you had it mostly right just the thing about the engine stroke is what you missed. Bored and stroke on a 318 and 360 respectively are the same both LAAnd magnum.

As far as the main bearing size they Are both also as they were with LA.
The only difference is that both magnum now take the same pan as each other/ which is more like the 360 LA.

I don't remember if I posted this part but part of why I started this thread was to ask about the difference between pistons for an LA vs a magnum 360.
I do know that Ive seen parts listings for pistons for the 318 that have stated within that a given part number can be used in either a 318 magnum or a 318 LA as long as the right rings for the respective set of pistons are used because they share bore and stroke size between them, and I know for a fact that they used exactly the same cranks in a 318 LA as they did for a 318 magnum. Both 318 LA and 318 magnum are neutral balance from the factory.
On the 360 (only) I know the pistons were different between the LA vs magnum, and rod length was the same but I'm not sure if they changed anything with the crank or rods on the 360 between the 2.
I have a 360 magnum I'm wanting to build and want to use up much if what I have laying around. To save on cost, bang for buck, etc. my 360 magnum block is a 30 over, so are the 360 LA flat top pistons I have. I'm pretty sure I could build it as a LA just using the magnum block and heads, and then could use the 360 LA pistons. Because I have the LA crank and rods.
I also have a couple of 360 magnum cranks that just need a polish and can be used at standard, and I do have stock 360 magnum rods. That's why I was wondering about being able to use the pistons I have if I did a balance job. And as long as I was doing a balance job (I've put together plenty of engines over the years but all pretty much stock, I've never had one balanced). Probably crazy thinking, I guess.

My wayward son, there'll be peace when you are done!

Great band.

If the motor is getting rebuilt with new pistons, and you’re planning on having it balanced anyway, the only “extra” cost will be the charges involved for installing however many pieces of heavy metal need to be put into the crank to make up for the external weights you’re removing from the damper and flywheel…….. plus the cost of the heavy metal itself.

If you weren’t planning on new pistons, then you’d also have to add in the cost to R&R the pistons on the rods.

Depending on what the shop labor rates are in your area, I can easily see that job costing $600+.
Just make a few calls.

Then you’ll need to come up with a neutral balance damper and flywheel.

Totally not worth the $$$$ for that type of build imo.
But it’s your money.

When I had the machine work done on my 97 5.9 Magnum. I asked about having it neutral balanced. He said it could be over 700.00 depending on how much Mallary was used.