318-360 lock up torque converter swap

[Bronze Barracuda]

I have a lock up torque converter from my 81 727 that was behind a 318. I was planning on using a torque converter from a 360 that I have..
I thought the torque converter from the 360 was a lock up as well but it is not.
I'm using the transmission from the 318 for the 360. I know the 318 TC's won't work unless you add the weight from the 360 TC. Or get a B&M flex plate. Since this is a budget build I was planning on welding the weight into it, but two questions come up, where do you weld it and does the weight of the weld play into the final result. Also heard that you shouldn't weld the weight onto a lock up TC as the heat will destroy it?
Any thoughts? Greatly appreciated.

 

[Professor Fate]

I have a lock up torque converter from my 627727 that was behind a 318. I was planning on using a torque converter from a 360 that I have..
I thought the torque converter from the 360 was a lock up as well but it is not.
I'm using the transmission from the 318 for the 360. I know the 318 TC's won't work unless you add the weight from the 360 TC. Or get a B&M flex plate. Since this is a budget build I was planning on welding the weight into it, but two questions come up, where do you weld it and does the weight of the weld play into the final result. Also heard that you shouldn't weld the weight onto a lock up TC as the heat will destroy it?
Any thoughts? Greatly appreciated.

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It matters a LOT where it is welded on and what size it is- that's how it balances!
Take careful measurements where the weight is located on the 360 convertor, in relation to the offset convertor lug. Measure and mark the lockup convertor in the EXACT same spot.
Then carefully grind the tack welds off the weight onto the 360 convertor, being careful not to alter the size or shape of the weight itself. Then tack weld the weight in the same way on the lockup convertor- no need for full welds, a couple of solid tacks like the factory did is plenty. You're done.
Alternately, if you're not comfortable cutting the welds off on the 360 convertor, shape an identical thickness piece of metal to the exact same size and shape as the 360 weight and tack that on.
You won't destroy the lockup by welding the weight on (the factory did, after all) unless you get carried away and start blowing holes in it.

 

[mygasser]

it sounds from the questions you asked like you'd be better off buying the b&m flexplate to be honest.
neil.

 

[Bronze Barracuda]

it sounds from the questions you asked like you'd be better off buying the b&m flexplate to be honest.
neil.

Yeah agreed to a point. I guess it comes down to how well I feel about my skill level and the budget I've got figured in. Done a little digging, I've only read good stuff on the B&M flexplate. I suppose if you know you've got a decent TC the flexplate option is still a lot better than a new TC?!

 

[Bronze Barracuda]

Looks like I may be lucky. The original torque converter had the butterfly weight on it still has the weld marks. Which should make it very easy to locate the proper location.

 

[Professor Fate]

Make sure you get the location EXACTLY right; "approximately" may not cut it.

 

[RustyRatRod]

Approximate WILL not cut it. @Professor Fate is exactly right. I'd use the B&M unit.

 

[Bodyperson]

Mopar Performance used to make a "kit" that came with a weight and a template. I don't think they are offered anymore. The weren't much of a savings compared to the flexplate.