Flex Plate Question.....

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Raupleminze

Raupleminze

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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?
 
B&M 10236 is the correct one for LA 360 with 727
 
no..1995 360 is a Magnum....

LA 360s were discontinued in 1991...
 
In your situation you might want to pop the pan off and verify if it is balanced internal or external, this way you will know for sure. You could build the engine either way but most internal balance these days, don't matter which year it is.
 
to internally balance it ..there are going to be some slugs of mallory metal in the crank counterweights...
 
I wouldn't go knocking the weights off of the converter just yet. If it was for an internally balanced 340 it should be neutrally balanced already. There are weights even on a neutrally balanced converter. If it is for an externally balanced 340 that is a diff story. If it is indeed a neutral 70 340 converter DO NOT knock the weights off. Then it will be who knows what.... If your 360 is externally balanced to mag specs just install the B&M 10242 and you will be golden. If it balanced to earlier L/A specs like the builder stated use the B&M 10236. I just went through this w my bro in laws 67 barracuda. He removed the 340, threw a L/A 360 in it and it vibrated pretty bad. He bought the B&M flex plate installed it W/O removing the weights on the converter (was already neutral balance) now it don't vibrate @ all. !st off you need to find out if your engine has been balanced or not. External Harmonic balancer?
 
Just looked @ your previous threads and photos. That weight on the converter looks as though it is for an externally balanced engine. Your harmonic balancer looks like an internally balanced balancer. Id look @ the crank for Mallory as others have already stated. If the converter has not been altered and is indeed for a 70 internally balanced engine, Leave it be. Weight could have been way off and just needed alot to neutral balance it. Go w/ builders note and buy the B&M earlier L/A flex plate. The builder should know best. I have a 98 mag 360 w a 71 rotating assembly so I would need to do the same. I know that because I put it together. Could be a nightmare for someone if I sold it and didn't tell them.
 
probably going to have to disassemble the engine..take the rotating parts to machine shop and the balance checked.....otherwise you are guessing...

you say it is 1995 360 with is a magnum...they are not balanced the same as a LA...but you say it is balanced to LA specs....

or just roll the dice....
 
BTW, now I have a B&M #10242 thats never been on a car for sale if anyone is interested. PM me.
 
I wouldn't trust anything your engine builder said per your previous statements. The pan would be off in a New York minute if it were me.
 
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