TC flex plate

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dancinwulf

dancinwulf

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I have a 70 Duster currently has a 318 with a stock TC I had the 727 completely gone thru
two years ago when I put the 318 in it. I am about to put a 340 in mostly stock a 71 motor
but want to change out the TC the one with the 318 is pretty sluggish. I will be driving it during the summer as we have loads of snow here in the winter so mostly a daily driver might run it out once in a while. Any suggestions as to brand and stall speed, flex plate etc.
 
dancinwulf said:
I have a 70 Duster currently has a 318 with a stock TC I had the 727 completely gone thru
two years ago when I put the 318 in it. I am about to put a 340 in mostly stock a 71 motor
but want to change out the TC the one with the 318 is pretty sluggish. I will be driving it during the summer as we have loads of snow here in the winter so mostly a daily driver might run it out once in a while. Any suggestions as to brand and stall speed, flex plate etc.
Click to expand...
The easiest way is to get a stock, 1971 (matches your engine) 340 converter. Depending on who you believe, the stall speed was between 2200-2400. I know the 71 340 Duster I bought new had a stall speed, if my memory serves me right, of around those numbers. For the flex plate, what's wrong with a stock Mopar one? Millions have been used by Chrysler. There are only 4 of them, 2 -11" ones and 2 -12" ones. The size is dependant on the converter, either its an 11" Converter (the ring gear is about 1" in width) and a 12" Converter, with a 1/2" wide ring gear. See the attached scan. Please note the mounting holes of the plate to the crankshaft.
I hope this helps you. With a mostly stock engine, I can see no reason to go to any other converter than a stock 340.
You should be able to get the flex plate from either your local Chrysler dealer or from any parts store like AutoZone etc. AutoZone I believe sells Daaco Converters, so they should be able to supply that to you also. If you've got any further questions, just ask.
 

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  • flexplates.pdf
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transman said:
The easiest way is to get a stock, 1971 (matches your engine) 340 converter. Depending on who you believe, the stall speed was between 2200-2400. I know the 71 340 Duster I bought new had a stall speed, if my memory serves me right, of around those numbers. For the flex plate, what's wrong with a stock Mopar one? Millions have been used by Chrysler. There are only 4 of them, 2 -11" ones and 2 -12" ones. The size is dependant on the converter, either its an 11" Converter (the ring gear is about 1" in width) and a 12" Converter, with a 1/2" wide ring gear. See the attached scan. Please note the mounting holes of the plate to the crankshaft.
I hope this helps you. With a mostly stock engine, I can see no reason to go to any other converter than a stock 340.
You should be able to get the flex plate from either your local Chrysler dealer or from any parts store like AutoZone etc. AutoZone I believe sells Daaco Converters, so they should be able to supply that to you also. If you've got any further questions, just ask.
Click to expand...
 
Will the flex plate that is on my TC on the 318 work is do I need a different one for the new TC I am trying to get everything I need so I can drop the trans and do everything at one time
 
dancinwulf said:
Will the flex plate that is on my TC on the 318 work is do I need a different one for the new TC I am trying to get everything I need so I can drop the trans and do everything at one time
Click to expand...
.
From the factory your 318/727 combo was supplied with a 12" converter. The 340/727 combo was an 11" converter and I think the flex plate is the larger one. I take it the 340 is out, so look at the crank to see if the mounting holes for the flex plate are even or uneven. Is there a flexplate with the 340? If so, and it looks good use it.
If not, then look at the flex plates in the file I sent you. You see that part number 12611 has uneven bolt holes while 12611A has even bolt holes. Don't pay too much attention to the part numbers for application. I know that part numbers 12611 and 12611A say they are for a Torqueflite 6 while part numbers 22611 and 22611A are for the Torqueflite 8, but that isn't necessarily so. What I'd do is know what the mounting holes in the crank look like, order the converter and then get the flex plate, with the proper crank mounting holes, and then match the flex plate to the mounting holes in the converter.
 
99.999999999999999999999999999999999 per cent chance that the 318 and 340 have the same number of crank bolts....6 ....
 
70aarcuda said:
99.999999999999999999999999999999999 per cent chance that the 318 and 340 have the same number of crank bolts....6 ....
Click to expand...
Yup, 6 crank bolts for sure, but some cranks have an even bolt pattern, some have a UNEVEN bolt pattern. See attached pdf. file. Pdf file shows the 4 flex plates Chrysler used. Always had to ask only two questions when someone wanted a flex plate, size and bolt pattern.
 

Attachments

  • flexplates.pdf
    423.2 KB · Views: 88
Thanks for the help no flex plate with the 340 but I will check out the crank and then go from there thanks again
 
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