360 Mag/904 this is what I have

My head is spinning. This is what I have.

Magnum 360 date stamp 1-12-93


We disassembled the 904 this morning. This was my first look at the workings of an automatic transmission. Thank the lord for good customers. That is Rick. I built a fence and two automated gate systems for him. He is helping me(doing) the rebuild on the transmission. That is his Barracuda in the back ground.

Now this is where I need a bit of help. I have searched all over for the answer and I must not be asking the right question. I know it's in here somewhere I just can't find it. Is this an external balanced torque converter?
I also have this flex plate. on a junk 360 magnum I picked up.

So what do I need ?
I love this place by the way. I have had so many questions answered here. Oh yea this will be the heart to this. My 73 dart swinger.

This is also my first build on a car. I have been wrenching out of necessity all my life. This I am doing for fun.

The converter is NON-WEIGHTED. Chyrsler weights welded to the front (pilot side) cover of the converter. Are their any part numbers on the converter, or any tags? It looks like it might be a rebuilt unit as the factory doesn't paint converters. As it has a narrow ring gear on it, it's a 12" unit. Any idea what the transmission came out of and what year it is?

That's about all I can tell you from the photos.

The trick here is to use a neutral balanced converter( no visible attached welded weights),and a 97 on up counter weighted Magnum 5.9 flex plate. (the picture you show of the flex plate, looks like a counter weight at 9 o'clock.Not positive for sure, without looking at mine). Once that's sorted out, match up the torque converter bolts. You probably will need to offset one,quite common.
WWW.Magnumswap.com:
Automatic Transmission Details
The Magnum engine uses the standard small block bellhousing bolt pattern, allowing for the use of 904, 727, etc. If you already have a small block V8 transmission, the engine will bolt up, but there are some important details to address first.

External Balance
The 5.9 Magnum engine is externally balanced and is different than all other Chrysler small blocks. The 5.2 Magnum is internally balanced and similar to the LA 318 in this respect. 5.2 users can ignore much of what is stated below.

The LA 360 is NOT the same as the 5.9 Magnum, and using the flex plate, balancer, or converter for an LA 360 will result in vibration and engine damage. You must use the correct parts!

LA 318s and steel crank 340s, and 5.2 Magnums are neutral-balanced, so there are no weights on either the flexplate or the converter. Conversely, externally balanced Chrysler small blocks have one of two arrangements. Either the flexplate has counterweights and the converter is “neutral” balanced, or the converter carries counterweights and the flexplate is neutral-balanced.

The 5.9 Magnum uses a weighted flexplate and a neutral-balanced converter from the factory. To make life simple, be sure to get the flexplate with your engine. With the weighted flexplate, simply use a neutral balanced converter, these are readily available for most transmissions. We recommend this method.



When you attach your converter, you will likely have a slight mismatch on one of the bolt holes on the Magnum flexplate. You will need to slightly enlarge one of the holes for proper fit. We recommend a decent sized rat-tail file, which makes quick work of this task.

If you do not have a stock magnum flexplate, you will have to run a neutral-balanced 360 flexplate and use a Magnum-balanced converter. Custom converter shops, like Ultimate Converter can build a converter balanced for a Magnum, but finding shelf converters balanced for Magnum engines is difficult if not impossible.
Hope this helps some,good luck.

Looks like the only thing is a "C" ? Stamped on the front side. The paint looks like over spray.

The transmission has the partial throttle kick-down. If that helps.

Caveman said:

Looks like the only thing is a "C" ? Stamped on the front side. The paint looks like over spray.

The transmission has the partial throttle kick-down. If that helps.

Click to expand...

As long as there are no visible welded weights,you should be good. I would take the time now,match the converter pilot hub & torque converter measurements, make sure they fit now. Not much luck on identifying stock converters,without a ATRA catalog.Post 2 is you're guy......

Good information here^^^....

So you know a counter weighted converter when you see one here's a picture. As you'll see they place the balance weight (for the engine) on the front side of the converter. There may also be a thin strip or 2 of steel around the outer perimeter of the converter to balance the converter itself but they have nothing to do with balancing the engine. Your picture of your converter shows one at approx. 10-11 O'clock

fishy68 said:

Good information here^^^....

So you know a counter weighted converter when you see one here's a picture. As you'll see they place the balance weight (for the engine) on the front side of the converter. There may also be a thin strip or 2 of steel around the outer perimeter of the converter to balance the converter itself but they have nothing to do with balancing the engine. Your picture of your converter shows one at approx. 10-11 O'clock

Click to expand...

Thanks,Tracy.... I was hoping ,for the riveted stamp,on the side . That might be removed , now.....

fishy68 said:

Good information here^^^....

So you know a counter weighted converter when you see one here's a picture. As you'll see they place the balance weight (for the engine) on the front side of the converter. There may also be a thin strip or 2 of steel around the outer perimeter of the converter to balance the converter itself but they have nothing to do with balancing the engine. Your picture of your converter shows one at approx. 10-11 O'clock

Click to expand...

This is what I was looking for. The flex plate does look like it is weighted. I will check and adjust fitment today. Thank you gentlemen.

Abodybomber said:

Thanks,Tracy.... I was hoping ,for the riveted stamp,on the side . That might be removed , now.....

Click to expand...

don't remove that weight plate by your hand, that's the convertor balance.

I am in good shape Gentlemen ! Thanks ! This issue was one of the biggies I was facing.
Glad I had everything needed to assemble the torque converter. Well except the bolts that attach the Flex plate to the torque converter. That will happen tomorrow.

Do you have any idea what year the transmission is, and as Bob mentioned don't remove that weight as it is the weight for converter balance.
Also, look closely at the hub of the converter. It must be mirror smooth, just like a crank journal or you'er looking at trouble. You can rip the seal, or worse damage the front pump bushing.

Typically, most stickers, or numbers use to help identify Chrysler converters are on the pump half (the half with the hub) of the converter.

I picked up on that balance the converter then the balance of the 360 aspect. I won't remove the weight.
No I have no idea what year the transmission is just know I will have an almost new one when we get it done. I think I was told 74 charger. i will have to look into reading that as well.