5.9 Weighted Flexplate

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1994redram

1994redram

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I pulled the 5.9 out of my wrecked '94 ram and plan on using it in my '70 dart. I was looking at the flex plate and it's a neutral balance while the convertor on the 518 trans is weighted. I've replaced that transmission several times over the years from hot-rodding the truck around. I've bought the weighted convertor by simply giving the year make and model of truck.

Since I plan on using a 727, I'll need a weighted flexplate. Which years used them? And are the aftermarket ones any good?
 
Only weighted flexplates are aftermarket. The usual ones used are B&M. I'm pretty sure they have one for the Magnum application, but I don't have the # handy.
 
I believe they went to a weighted 5.9 OEM flex plate and nuetral balance converter in 1996. I paid 35$ for one at the junkyard. Just tell them you need the later flexplate. I did the one hole elong mod and run a nuetral balance converter with 7/16" bolts.
 
Locomotion said:
Only weighted flexplates are aftermarket. The usual ones used are B&M. I'm pretty sure they have one for the Magnum application, but I don't have the # handy.
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I helped a friend install a 5.9 magnum in place of a LA 318 in his '74 D100. His 5.9 had a factory weighted flex plate and needed one of the holes opened up a bit. We unded up using the entire harness and electronics from a 94-95 ram and keeping the EFI.
 
I stand corrected on the OEM weighted flexplates! Learn something new every day.
 
So you are doing what? Carbureting a magnum? Putting it against a 727? I see no reason you can't use the OEM weighted flex out of your truck
 
67Dart273 said:
So you are doing what? Carbureting a magnum? Putting it against a 727? I see no reason you can't use the OEM weighted flex out of your truck
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My flex plate is neutral, like a 318 would be. The trucks 518 converter is weighted. And that is my problem. I'm using a 727 instead of the 518 and my 727 is neutral balanced.

If anyone needs a good 518 trans, I would happily trade it for a weighted flex plate! I had a hard time through school trying to save up and buy/rebuild the 518's after I tore them up. Now I can't even sell this thing for $250. The demand is gone I suppose
 
If I understand correctly the converter you are wanting to use in the 727 is weighted. But being you have a 5.9 Magnum engine, you would need the converter weight to be correct for that unique balance engine and then use a neutral flexplate. For simplicity Id knock the weight off of the converter and use the Magnum Mopar weighted flexplate listed above. You obviously wouldnt want both the converter and flexplate weighted.

But if the 727 converter you are using is neutral, then a B&M 10236 weighted flexplate is the one you want.
 
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1994redram said:
My flex plate is neutral, like a 318 would be. The trucks 518 converter is weighted. And that is my problem. I'm using a 727 instead of the 518 and my 727 is neutral balanced.

If anyone needs a good 518 trans, I would happily trade it for a weighted flex plate! I had a hard time through school trying to save up and buy/rebuild the 518's after I tore them up. Now I can't even sell this thing for $250. The demand is gone I suppose
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First the 518 converter should not be weighted. The 518 FLEX PLATE should be weighted. If you elongate one hole, you MIGHT be able to use the 518 flex

Otherwise, you need to order a BM aftermarket weighted flex FOR A 5.9 MAGNUM (NOT a 360LA)
 
If the 727 trans and converter are neutral balance, you'll need the flex plate that goes with the 5.9. The 5.9 flex plate and harmonic balancer are matched to the 5.9 to externally balance the motor. It too needs one converter hole elongated. The 5.2 flex plates are neutral balanced and need one converter hole elongated to fit the 727 converter.

I have two 5.9 flex plates in my garage. Pay for the boxing and shipping, and I'll send you one.
 
67Dart273 said:
First the 518 converter should not be weighted. The 518 FLEX PLATE should be weighted. If you elongate one hole, you MIGHT be able to use the 518 flex

Otherwise, you need to order a BM aftermarket weighted flex FOR A 5.9 MAGNUM (NOT a 360LA)
Click to expand...
I haven't read much about the magnum weights being on the converter. But... it is. And I've bought a few converters over the years when I replaced the transmission in the truck. I ordered the converter for the year, make, and model, they've always been weighted.

mderoy340 said:
I believe they went to a weighted 5.9 OEM flex plate and nuetral balance converter in 1996. I paid 35$ for one at the junkyard. Just tell them you need the later flexplate. I did the one hole elong mod and run a nuetral balance converter with 7/16" bolts.
Click to expand...
I'm thinking your correct. I have a '94 model engine. Which would be before the time of weighted flexplates if your statement is correct.
 
My 2001 magnum 5.9 had a weighted flex plate so I mated it to my 904 with a neutral converter. Did have to enlongate one hole though.
 
Not sure, found out about it helping a friend and installation hasn't happened yet.
 
1994redram said:
.................. I have a '94 model engine. Which would be before the time of weighted flexplates if your statement is correct.
Click to expand...

That could be. I have a flex off a 97--ish magnum 5.9 and there is NO doubt the converter is neutral and the flex is weighted.

Be careful you do not get a converter / flex that is weighted for a 360LA. They are weighted differently than a Magnum 5.9
 
I'll take jbc426 up on his offer to pay for shipping and handling. But his inbox is full currently.


What's sucks is my dad put a motor in his '94 ram and had the flexplate from the replacement '99 5.9. That motor was bad and the salvage yard told him to keep it and they gave him another good 5.9. He used his original flex and had the two weighted flexplates kicking around. I thought about keeping them as I was helping him clean the garage up. But they got tossed.
 
Not intending to drag this around any more than necessary, but i am about to do a 5.9 magnum swap into my 80 power wagon, keeping the efi. This sort of swap is new to me but im up for the challenge.
Just want to say thanks for the insight into the flex plate, first problem solved.
 
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