340/904 flexplate

Posted By: 71Polara383

340/904 flexplate - 07/07/13 05:42 AM

What flex plate is needed to use a 904 behind an external balance 340? Was gonna build a 360 but plans changed. The converter I bought is for external balance small blocks. Its a boss hog 2800 stall for a 904

Posted By: 70AARcuda

Re: 340/904 flexplate - 07/07/13 05:46 AM

Quote:

What flex plate is needed to use a 904 behind an external balance 340? Was gonna build a 360 but plans changed. The converter I bought is for external balance small blocks. Its a boss hog 2800 stall for a 904

the amount weight for externally balanced 340 and 360 are different...

can not use a externally balanced converter for a 360 on a externally balanced 340....need to knock weights off converter and get B&M weighted flexplate for externally balanced 340.

Posted By: 70AARcuda

Re: 340/904 flexplate - 07/07/13 05:49 AM

http://www.summitracing.com/parts/bmm-10235/overview/make/dodge

only shows for 727....

what is the bolt circle of the torque converter...

Posted By: 71Polara383

Re: 340/904 flexplate - 07/07/13 06:17 AM

10'' bolt pattern. I can just knock the weight off my converter?

Posted By: MoparforLife

Re: 340/904 flexplate - 07/07/13 08:39 AM

That is right - just knock the weight off if you have a internal balanced 340.

Posted By: 71Polara383

Re: 340/904 flexplate - 07/07/13 10:29 AM

The motor I'm considering is a 72 cast crank 340 with external balance. My 360 is trashed picking up the 340 motor this week hopefully.

Posted By: MoparforLife

Re: 340/904 flexplate - 07/07/13 01:41 PM

In that case you will need the flexplate for a cast shaft 340 or a converter weighted for a cast shaft 340. BUT if you get the flexplate you will need to take the weights off the present converter as as you cannot use both a weighted converter and flexplated for a cast shaft. And the 360 weighting is different.