Flex Plate Question.....

Hey Guys,

Bought an engine a couple years ago that was built by a machine shop. They builder has been impossible to get a hold of to ask this question so I figured I would ask you guys for help.

The engine specs are as follows:

360 Plate Honed-Decked Square
.040 over KB #107 Flat top pistons
File Fit Rings 5/64's
Stock Rods Resized w/ARP Bolts
Stock 360 Crank 010/010
Clevite Bearings
New Standard Volume Pump
Stock Pan w/New Pickup
Comp Double Roller Timing Set
Mopar Chain Tensioner
Mopar Performance Hydraulic Roller Cam
230-234 @ 050 464 478 Lift 107 LSA
Mopar Stamped Rockers 1.5 Ratio
New SBI Lifters
"587" 360 Heads 1.88-1.60 Valve
Crane Springs, B Ported and Gasket Matched
74 cc

Stock 360 balance will need B&M Flexplate for early 360 or 360 weighted converter or Mopar 360 flywheel for early 360 like a 70's model
NOT magnum balance

This will be bolted to a rebuilt 727 transmission out of a 1970 340 car. It has a brand new torque converter that is balanced for a 340. I have been told that I need to knock the weight off so that its neutral (unbalanced) and run B&M flexplate #10242 (which has already been purchased).

Previous Threads:
http://board.moparts.org/ubbthreads/show...rue#Post6865608

http://board.moparts.org/ubbthreads/show...rue#Post6704904

However my concern is that with the engine notes that were given to me the engine builder specifically states "Stock 360 balance will need B&M Flexplate for early 360 or 360 weighted converter or Mopar 360 flywheel for early 360 like a 70's model NOT magnum balance". And if I am reading things correctly the B&M Flex Plate #10242 is for a 93-99 360 which I believe are magnum balanced.

B&M #10242
http://www.jegs.com/i/B%26amp%3BM/130/10242/10002/-1

I am thinking maybe that he is talking about using this one:
http://www.jegs.com/i/B%26amp%3BM/130/10236/10002/-1

What do you guys think?