LA vs Magnum Balance

-
6pak

6pak

Member? - can’t Re-Member
Joined
Nov 15, 2013
Messages
152
Reaction score
95
Location
ESVA
I’m not concerned w the 318. But what is the difference in external balance between the 360 LA and Mag?
A lot? Enough to be concerned if not racing?
I’d like to used original parts because I am cheap but have a couple questions.
Mag 5.9 flexplates only bolt to 727 circle pattern converters, right?
I have B&m cutout plate for LA & 904. I’m running A500 in my truck.
I will probably never run it past 4.5k. And just be trying to get MPG every time else.

see any problems?
 
LOLOL You need to tell us what the combo is.........guessing.................

If you are running an old style auto against a Magnum, run the magnum weighted flex, knock the 360 weight (if present) off the LA converter, and elongate one hole on the Magnum flex to fit the odd bolt on the LA converter

But if you are going to run an A-500 what is the problem? Don't they use a symmetrical bolt pattern converter?

!!!****!!!! We could guess all day at this. YOU NEED TO POST WTF you are going to run LOLOL
 
Ok. Maybe not enough info.
Current LA 360 has a B&M cutaway flexplate. That bolts to the current A500. Running with no issues.
I’m swapping out to a rebuilt 5.9 Mag.
Will the LA balanced Flex Plate be a problem?
 
6pak said:
Ok. Maybe not enough info.
Current LA 360 has a B&M cutaway flexplate. That bolts to the current A500. Running with no issues.
I’m swapping out to a rebuilt 5.9 Mag.
Will the LA balanced Flex Plate be a problem?
Click to expand...
The amount of offset weight is different between LA and magnum. Assuming the rebuilt magnum has stock weight internals, you should be able to use a factory weighted flexplate for the magnum engine and be ok, NOT the b&m one, it's not correct for the magnum
 
Please clue me what to look for.
I don’t think 5.9s ever drove A500s. This trans came from behind a 5.2.
 
And I’m thinking stock 5.9 flexplate torque converter mounting holes will not line up with the A500.
 
93-03 magnum external balance is 14in/oz.
71-92 LA 360 external balance is 19.8in/oz
Get the balance right or it’ll shake like a pup poopin a peach seed.
 
TT5.9mag said:
93-03 magnum external balance is 14in/oz.
71-92 LA 360 external balance is 19.8in/oz
Get the balance right or it’ll shake like a pup poopin a peach seed.
Click to expand...

Now here is someone who sounds like they know what they are talking about.
If you could just explain the in/oz thing. LOL.
Rather than people who can’t read a question and have to interject their “”Gold Member” advise.
 
Lol there are much smarter people here than me.
It’s an amount of weight and a distance relative to centerline required to balance. Imagine one pound of weight, one inch from center. Then imagine one ounce 100 feet from center. The concept is relatively easy to understand. But this has all been figured out for you. B&M used to make two cutout flexplates, one for mag and one for LA if I remember correctly. Not sure if they still do. But it will be all the same stuff used to put a 904 behind a 360mag. Use the mag harmonic balancer, the stock mag flexplate, elongate one of the holes with a die grinder so it bolts to the neutral balance converter and you should be golden. Assuming your rebuilt mag was externally balanced as it was stock.
 
TT5.9mag said:
Lol there are much smarter people here than me.
It’s an amount of weight and a distance relative to centerline required to balance. Imagine one pound of weight, one inch from center. Then imagine one ounce 100 feet from center. The concept is relatively easy to understand. But this has all been figured out for you. B&M used to make two cutout flexplates, one for mag and one for LA if I remember correctly. Not sure if they still do. But it will be all the same stuff used to put a 904 behind a 360mag. Use the mag harmonic balancer, the stock mag flexplate, elongate one of the holes with a die grinder so it bolts to the neutral balance converter and you should be golden. Assuming your rebuilt mag was externally balanced as it was stock.
Click to expand...

I appreciate it Brother.
This Makes sense. And sounds like a good answer. I will certainly look into it. I don’t think anyone has addressed this before. If they have, google doesn’t have results for it!
I had no idea a 5.9 mag flexplate could be made to work with a 904 torque converter bolt pattern.
- And, are you sure?
I’m going to look into it. Using stock pieces is my game.

I have been a member of this forum for a while and tried to use it for information and seen sooooo many threads get hi-jacked, and everyone has to put in what their friends/dad’s/ Mom’s car had and did.
I know my original question may have not been clearly stated. &
I apologize to all the “goldies” I may have offended.
I’ve been around a while, and tend to observe, rather than report!
 
I have personally put a 904 behind a 2001 5.9 mag and all I did was cut a notch for the crank sensor and open up one hole on the stock flexplate. Ran that way for years.
 
I'm running an A518/46RH behind a 5.9 Magnum. I used the stock Magnum weighted flexplate, one hole elongated to fit, with the neutral balanced torque converter that came with the transmission. Thing runs smooth as silk. Essentially the same transmission as the A500.
 
6pak said:
I appreciate it Brother.
This Makes sense. And sounds like a good answer. I will certainly look into it. I don’t think anyone has addressed this before. If they have, google doesn’t have results for it!
I had no idea a 5.9 mag flexplate could be made to work with a 904 torque converter bolt pattern.
- And, are you sure?
I’m going to look into it. Using stock pieces is my game.

I have been a member of this forum for a while and tried to use it for information and seen sooooo many threads get hi-jacked, and everyone has to put in what their friends/dad’s/ Mom’s car had and did.
I know my original question may have not been clearly stated. &
I apologize to all the “goldies” I may have offended.
I’ve been around a while, and tend to observe, rather than report!
Click to expand...

I don't have a dog in this hunt, but a couple of things. First, your original question was indeed less than vague. Forgive some of us if we ribbed you for maybe a little more information. This is a car site, after all and as such has car guys on it which are known for being a pretty sarcastic bunch. Most of the time......as is the case here, it is meant with all the brotherly love and ribbing as possible. Nobody meant you any malice. We're all a big family.

The next point you may want to consider is, some people, such as myself for instance, are gold members not of their own doing. I've been gifted gold memberships for a few years in a row, as I am quite sure so have others, so the fact that someone is a gold member, shouldn't be held against them, or mocked.

Also, gold members support the site financially, whether from their own purchase of a gold membership, or being gifted one. The cost is the same. I would think that everyone would be glad people are actually supporting this great site, so that anyone, whether they pay for a gold membership or not, can be a member and reap all of the great benefits from the vast knowledge base we have here. For free.

I'm kind of surprised someone with obvious intelligence such as yours would poke insults at our gold members. All of them are the reason this site still exists and is able to help people like you and so many others. Joey and his mod staff run a fantastic site and they should be thanked.....regularly. I consider an insult to gold members......and any member really in the way you did it a slap in the face to every staff member, gold member and regular member here.

You should be ashamed of yourself.
 
6pak said:
And I’m thinking stock 5.9 flexplate torque converter mounting holes will not line up with the A500.
Click to expand...
You might be right, here is what you could do.........

Scare up a stock factory 5.9 mag flex plate. This will give you a weight and the rotational and radius position of the weight. cut the weight off and carefully attach it to the flex of a 5.2 flex made for an A500 trans or a 42/44RE (904 based) for a 5.2.

It may or may not be practical to re-drill the 5.9 flex. You could lay one over the other piloted by the center hole of the crank to get the pattern.
 
Seriously it’s pretty easy to use a stock 5.9 flexplate here guys.
5745D695-21E0-48EC-A9CF-E2668F05DECA.png

This is the amount of offset of ONE hole that needs to be elongated. I mean if this level of modification is beyond your scope you should consider another hobby. Not poking at anyone in particular. But cutting off weights and rewelding them and trying to get the balance correct is really much more difficult. Find a neutral balance torque converter for your trans. Use all the stock 5.9 mag stuff, flexplate and harmonic balancer. Elongate ONE HOLE. Install everything, drive to get donuts. It’s that easy.
 
Last edited:
B&M magnum flexplate on a neutral B&M flexplate

2nd picture Magnum flexplate on a B&M LA 360 flexplat

20200123_165320_resized.jpg


20200123_165410_resized.jpg
 
I run a 904 behind a 5.9 using the 5.9 flexplate and dont recall having much of an issue . Must have elongated the hole but it wasnt enough work to remember .
 
I dont know squat. I aint offended. Im gold because I like to pay for what I get. GO GOLD BABY!

(and Im not callin you a baby.....)
 
Ok. Thanks.
I’m gonna spring for a 5.9 flexplate. Don’t know if the A500 torque converter holes will line up, but they make great crankshaft stands. !!
 
You must log in or register to reply here.
-

Back
Top