273 torque converter

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MassDart

MassDart

Lifelong Dart fan
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If I understand correctly, the 273 is an internally balanced engine. Am I correct to assume then, that the stock torque converter is unweighted? I ask because I'm going to be installing a 360 magnum into the car that has the weighted harmonic balancer and flex plate. Do I need to pull the converter and remove weights, or am I good to go?
 
If the 360 flex plate is weighted, I think your good but I would wait for others to respond as I could be mistaken.
 
That 273 convertor, if 66 or older, will not fit the Magnum crank. Well it will but has no nose support and nothing to to keep it spinnining concentrically withe the crank. But
if 67 or newer, then no problem. butas Kendog says, you will need to install the properly weighted flexplate.

But IMO, the 273 2bbl convertor stalls very low, which is fine for a DD, but if yur looking for performance, then now is the time to upgrade.
 
Yes, the converter is neutral balanced.

Yes, you need an offset balanced flex plate or the weight set and weld them on.

Yes, you will need an annular ring because of the front snout size difference. Check the inside diameter of the magnum crankshaft and report to member “CharlieS”, he makes and sells the annular rings to make up this difference. Most go into standard LA motors, that’s why you need to actually measure your magnums register size.
 
Your 5.9 Magnum needs the harmonic balancer and flex plate it has on it. If your converter is a 68 and up, the nose of the converter and the crank register may match up, but be sure and measure them both as mentioned above. You will need to oval one hole in the 5.9 Magnum flex plate for your existing converter to bolt up. Your existing converter should have no weights welded to the face of it. I'm sure you will change the front seal in the transmission during the process. Have fun with the swap. It should wake your car up a bunch!
 
Thanks all! I have the correct harmonic balancer and the correct B&M flexplate. I also purchased the bushing for the nose of the converter, so if it's a neutral balanced converter, I guess I'm good to go. The Magnum I built is to the Mild Magnum build which should be around 410 hp and around 450 torque if I remember correctly, so the converter, while not optimal should be okay as a warm street/driver until I marshall up the funds and pick up a 727 and a proper torque converter. I'm also finishing up building an 8 3/4 with SG and 3.55's so it should scoot pretty good.
 
Double check your part number on your B&M Flex Plate to make sure they didn't send you one for an LA 360 instead of a 5.9 Magnum. The balance is different between the two. If they sent you the wrong one it will make your motor sh sh sh sh shake! :eek:
 
MassDart said:
If I understand correctly, the 273 is an internally balanced engine. Am I correct to assume then, that the stock torque converter is unweighted? I ask because I'm going to be installing a 360 magnum into the car that has the weighted harmonic balancer and flex plate. Do I need to pull the converter and remove weights, or am I good to go?
Click to expand...
There is no weighted flex pate. There is one from B&M with a "bite" out of it for balance.
 
That one is for an LA 360. I think the one for a 5.9 Magnum is an AA242. They say it's for 360 (5.9) Magnum to a 727, but it appears to have both sets of holes. I'm not trying to be argumentative....I just don't want you to put all that mess together and then have to take it back apart if it shakes because of the wrong flex plate. a 5.9 Magnum and an LA 360 are balanced differently even though they are both 360's.
 
Interesting. I'll have to call them again. When I ordered it, I specifically asked if this was the one for the Magnum and 904 and they said it was. I'll call them again and find out. Thanks for the heads up. I didn't question it because it referenced the B&M number.
 
Do you still have the 5.9 Magnum flex plate that came off of your motor? I am not sure if a 904 converter will bolt to it or not, but I could check for you tomorrow if you'd like. I have the factory flex plate from my 5.9 Magnum and a few 904 converters laying around to check with if yours isn't out of the car where you can get to it.
 
I don't have the original plate, but a conversation with Mancini this morning confirms that AA241 (aka 10241) is the plate for Magnum to 904. At least according to them.
 
cosgig said:
Yes, the converter is neutral balanced.

Yes, you need an offset balanced flex plate or the weight set and weld them on.

Yes, you will need an annular ring because of the front snout size difference. Check the inside diameter of the magnum crankshaft and report to member “CharlieS”, he makes and sells the annular rings to make up this difference. Most go into standard LA motors, that’s why you need to actually measure your magnums register size.
Click to expand...
Okay, last question on this, I promise. I have that annular ring and am getting ready to do the swap. On that ring, do I put it on the nose of the converter and then install the engine, and do I need to grease it or anything?

Thanks!
 
AJ/FormS said:
That 273 convertor, if 66 or older, will not fit the Magnum crank. Well it will but has no nose support and nothing to to keep it spinnining concentrically withe the crank.
Click to expand...
I thought that was only a/6 thing
 
MassDart said:
Okay, last question on this, I promise. I have that annular ring and am getting ready to do the swap. On that ring, do I put it on the nose of the converter and then install the engine, and do I need to grease it or anything?

Thanks!
Click to expand...
You can grease it up a little, and I would probably put it in the crank register first.
 
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