LML crank in lb7 engine build, which flexplate?

The Kansan

New member
Aug 30, 2013
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Topeka, KS
Im collecting the rest of my parts to complete an engine build and i figured someone on here would know what flexplate to run with and lml crank. I have a socal lb7 flexplate and was wondering if it will balance up fine with a lml crank or if i need to sell it and get something different. It will be an externally balanced rotating assembly. Thanks
 
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S Phinney

Active member
Aug 15, 2008
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Quncy, Fl
Guy may have the answer but he most likely will have to spin up. The Bob weight will determine a lot on this. What will you use for pistons and rods? Do you have any weights on these? The crank us very similar to the lb7 but that doesn't mean much in the equation.

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juddski88

Freedom Diesel
Jul 1, 2008
4,651
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Chesterfield, Mass.
Since the rest of your rotating assembly weight is changing anyhow, it isn't going to matter too much what balancer or fly wheel you use, it is going to need to be balanced all as one anyhow. I used lbz stuff with mine because either is what I had, and we still had to remove a bunch of mass from a few counterweights
 

calereeves

Displaced Texan
Jul 13, 2011
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Just last night I ordered a SoCal billet flexplate and super damper, I'm using an LML crank in an LMM block. He asked specifically which crank I was using, so I'm assuming you'll need LML flexplate and balancer

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chevyburnout1

Fixing it till it breaks
Aug 25, 2008
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Berthoud, CO
Machine shop told me to try to keep parts matching to the crank, but again said it needs to be spun before any decisions can be finalized. I'm sending my LML crank in with an LML flex plate but my original LB7 SoCal damper.
 

S Phinney

Active member
Aug 15, 2008
4,011
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Quncy, Fl
I looked back through my emails or this matter for a customer. Guy told me that the bobweight for lb7 and Lly was 3400 grams and the bobweight for lbz and lmm was 3500 grams. Those where GM blueprint specs. He weighed the stock parts he had on lml items and came up with 3351 grams as the bobweight. Usually aftermarket rods and pistons will come up on the lighter side of stock. Some race cast 20 overs and howards rods I had came in around a 100 grams lighter if I remember correctly. Hope this information helps some. The likelihood of lb7 items being more compatible is pretty high..

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The Kansan

New member
Aug 30, 2013
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Topeka, KS
I just got off the phone with DHD, i was ordering a couple things and he said that the Lb7 balancer and damper have worked fine for them in this situation and to go ahead and have it balanced with the lb7 parts. I have a set of wagler rods and race cast 20 overs. Thanks for all the replies