Engine is a 70 440 Magnum with the 70-71-Magnum-specific external balance.

The transmission front seal blew out of my trans, in one day it went from an occasional drip to enough drips&runs to turn my car into a cropduster. I suspected this was more than a seal to start leaking so badly, and suspicions were confirmed.

The converter hub has a pretty wide wear patch on it, and I also noticed the converter has 2 ring gear teeth missing, which I could feel when starting the car (but didn't know what it was). The converter also has 2" tall lettering on the back side that has been painted over, so somebody has been in there before me (even though it's a 'survivor' car). I'm going to install a new pump bushing, seal, and new converter.

So:
I've looked and haven't found anyone that lists this specific converter, and I've looked unsuccessfully for the data on the weight size and location so that I could weld them onto an unbalanced converter. Anyone got any info? My car always had a slight vibration (could feel it in neutral when revving the engine) so I don't trust using my existing converter weights or as a pattern.

Help!

B&M makes a flex plate for that application, already for your new, unweighted TC. I have one on my 440 in the Charger.

Is this the one? They only showed 2 for external balance for a 440, 1 for steel crank and 1 for cast -- it doesn't specifically mention the balance setup and it says it fits 66-78 bigblocks (which is a very wide paintbrush!).

http://store.summitracing.com/partdetail.asp?part=BMM%2D10238&autoview=sku

B&M doesn't even list this part on their website, so no info there...

Get yourself a neutral balance converter and take the weights off the converter you have and weld them in place. Not a big deal to locate properly or to weld on. Easy and cheap to boot.
To locate lat the 2 converters side by side and locate the lug with the offset bolt in the same positions on both converters and then locate the weights in the corresponding position on the new converter.

Yeah, I've considered this but my car always had a slight vibration (could feel it in neutral when revving the engine slowly). I don't trust using my existing converter weights as a pattern unless I can find out that they are the right size and right location.

If anyone with a stock 70-71 440Magnum can take their inspection cover off, measure the weights and take a pic that would help me greatly! Or a tech drawing would work instead - I've seen this data on flywheel balancing but not found it for the converters...

B&M #10238 is the correct flexplate for the '70 440HP.

Use the steel crank externally balanced plate as John says, then you can swap converters till the cows come home.
R.