340 converter/360 crank flex plate? - Moparts Forums

Register Log In Moparts Forums Moparts Question and Answer 340 converter/360 crank flex plate?

Print Thread

340 converter/360 crank flex plate? #274631 04/01/09 11:25 PM 04/01/09 11:25 PM
Joined: Oct 2004 Posts: 2,820 Connecticut FurryStump OP master
FurryStump OP master Joined: Oct 2004 Posts: 2,820 Connecticut	Is the stock 1968 340 converter neutral balance. My 408 stroker motor calls for a "weighted 360 pre magnum flex plate" I'm using a b&m 10236 flex plate and a stock 340 converter. I have a small vibration that's bugging me. eliminating suspects b&m 10236 flex plate Chrysler '71-'92 externally balanced 360 with A-727 (These special Chrysler Flexplates must be used when changing converters on an externally balanced engine.) Is this considered a weighted flex plate? Thanks best of 11.39 at 117 mph 1.60 60’. 68 340 S Barracuda Fastback F.A.S.T [IMG]http://i67.tinypic.com/2mnnnnt.jpg[/IMG]

Re: 340 converter/360 crank flex plate? [Re: FurryStump] #274632 04/01/09 11:29 PM 04/01/09 11:29 PM
Joined: Jan 2003 Posts: 9,826 las vegas 70AARcuda master
70AARcuda master Joined: Jan 2003 Posts: 9,826 las vegas	Quote: Is the stock 1968 340 converter neutral balance. My 408 stroker motor calls for a "weighted 360 pre magnum flex plate" I'm using a b&m 10236 flex plate and a stock 340 converter. I have a small vibration that's bugging me. eliminating suspects b&m 10236 flex plate Chrysler '71-'92 externally balanced 360 with A-727 (These special Chrysler Flexplates must be used when changing converters on an externally balanced engine.) Is this considered a weighted flex plate? Thanks the stock 340 converter should be a neutral balanced converter..no weights...the weights are pretty obvious if you look at the converter... yes..that flexplate is for an externally balanced 360 and should have been used went the engine was balanced... how about the drive shaft??? pinion angle??? Tony 70 AARCuda Vitamin C 71 Dart Swinger 360 10.318 @ 128.22(10-04-14 Bakersfield) 71 Demon 360 10.666 @122.41 (01-29-17 @ Las Vegas) 71 Duster 408 (10.29 @ 127.86 3/16/19 Las Vegas)

Re: 340 converter/360 crank flex plate? [Re: 70AARcuda] #274633 04/01/09 11:50 PM 04/01/09 11:50 PM
Joined: Oct 2004 Posts: 2,820 Connecticut FurryStump OP master
FurryStump OP master Joined: Oct 2004 Posts: 2,820 Connecticut	I just replaced the forty year old transmision mount with a new poly mount. Before the change the trans squashed the old mount almost to nothing. The new mount moved the trans about an inch and a half higher. I figured the new mount would reduce any vibration. New u joints front/rear. I plan on turning the drive shaft 180 degrees to see if it helps. I just want to make sure I don't have the wrong flex plate in it. Other then a cut out it appears symetrical no weights, just the absence of weight. ie cutout. Everything I can find to explain which flex plate I need seems to fail in giving a definite answer.thanks best of 11.39 at 117 mph 1.60 60’. 68 340 S Barracuda Fastback F.A.S.T [IMG]http://i67.tinypic.com/2mnnnnt.jpg[/IMG]

Re: 340 converter/360 crank flex plate? [Re: FurryStump] #274634 04/02/09 12:26 AM 04/02/09 12:26 AM
Joined: Jan 2003 Posts: 9,826 las vegas 70AARcuda master
70AARcuda master Joined: Jan 2003 Posts: 9,826 las vegas	the cut out on the b&m flexplate is the same as having weights on it... the older flexplates had a weight...the newer externally balanced flexplate has a cut out..NO Weights...but the part number will tell ya what it fits... Tony 70 AARCuda Vitamin C 71 Dart Swinger 360 10.318 @ 128.22(10-04-14 Bakersfield) 71 Demon 360 10.666 @122.41 (01-29-17 @ Las Vegas) 71 Duster 408 (10.29 @ 127.86 3/16/19 Las Vegas)

Re: 340 converter/360 crank flex plate? [Re: 70AARcuda] #274635 04/02/09 06:19 AM 04/02/09 06:19 AM
Joined: Jan 2003 Posts: 25,200 Upper Midwest M MoparforLife Too Many Posts
MoparforLife Too Many Posts M Joined: Jan 2003 Posts: 25,200 Upper Midwest	Quote: the cut out on the b&m flexplate is the same as having weights on it... the older flexplates had a weight...the newer externally balanced flexplate has a cut out..NO Weights...but the part number will tell ya what it fits... WRONG!!!! No early flex plates had weights. OEM. Whether for small block or big block. Period!!!! There were to 2 sizes of flex plates used depending on the converter used. Either could be found on 727 transmissions. But NONE were weighted, only after market flex plates were weight compensated. OEM converters had compensating weights welded to them.

Re: 340 converter/360 crank flex plate? [Re: MoparforLife] #274636 04/02/09 08:26 AM 04/02/09 08:26 AM
Joined: May 2004 Posts: 1,522 Ste-Sophie, Quebec, Canada W Wedgeman pro stock
Wedgeman pro stock W Joined: May 2004 Posts: 1,522 Ste-Sophie, Quebec, Canada	The cut out is for the crank sensor on later models......I've been told.... Daniel

Re: 340 converter/360 crank flex plate? [Re: MoparforLife] #274637 04/02/09 11:19 AM 04/02/09 11:19 AM
Joined: Jan 2003 Posts: 9,826 las vegas 70AARcuda master
70AARcuda master Joined: Jan 2003 Posts: 9,826 las vegas	Quote: Quote: the cut out on the b&m flexplate is the same as having weights on it... the older flexplates had a weight...the newer externally balanced flexplate has a cut out..NO Weights...but the part number will tell ya what it fits... WRONG!!!! No early flex plates had weights. OEM. Whether for small block or big block. Period!!!! There were to 2 sizes of flex plates used depending on the converter used. Either could be found on 727 transmissions. But NONE were weighted, only after market flex plates were weight compensated. OEM converters had compensating weights welded to them. my reference to old flexplates is the old b&m 360 flexplates had weights on them...where as the new one had a cut out. Tony 70 AARCuda Vitamin C 71 Dart Swinger 360 10.318 @ 128.22(10-04-14 Bakersfield) 71 Demon 360 10.666 @122.41 (01-29-17 @ Las Vegas) 71 Duster 408 (10.29 @ 127.86 3/16/19 Las Vegas)

Re: 340 converter/360 crank flex plate? [Re: 70AARcuda] #274638 04/02/09 11:36 AM 04/02/09 11:36 AM
Joined: Jan 2003 Posts: 25,200 Upper Midwest M MoparforLife Too Many Posts
MoparforLife Too Many Posts M Joined: Jan 2003 Posts: 25,200 Upper Midwest	I interpeted it as the OEM plates had weights - none of which do. Sorry, thanks for the clarification.

Re: 340 converter/360 crank flex plate? [Re: MoparforLife] #274639 04/02/09 11:34 PM 04/02/09 11:34 PM
Joined: Oct 2004 Posts: 2,820 Connecticut FurryStump OP master
FurryStump OP master Joined: Oct 2004 Posts: 2,820 Connecticut	So I have an externally balanced flex plate on an ext balance engine with a nuetral balance converter. All is well with the world. Thanks best of 11.39 at 117 mph 1.60 60’. 68 340 S Barracuda Fastback F.A.S.T [IMG]http://i67.tinypic.com/2mnnnnt.jpg[/IMG]

Moderated by Al_Alguire, Hotwheelsjr, moparts, not_a_charger, RangerDan440, tboomer

Hop To

Powered by UBB.threads™ PHP Forum Software 7.7.1