Stan indicated a difference in the way the 396 crank is weighted when used in a 427. I would appreciate any info regarding this.
Dan

OK, I found my reference. The following is taken from "How To Build And Modify Chevrolet Big-Block V-8 Engines", by Tom Currao.

Under the chapter on crankshafts, "Another thing to watch for as you're building a 396 or 402 is that they use a different counterweight design than 427s. Although they share the same 3.76-inch stroke, the 396 and 402 crankshafts use a 7/16-inch wide #3 counterweight (third from front). 427s have larger, heavier pistons, which require 7/8-inch wide counterweights at every position to counterbalance the extra weight. So, keep this in mind."

Hope this helps. This book is commonly available and is loaded with info. I assume the info is accurate.

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Thanks Stan! Ill mention this to the machine shop. Was thinking of having the entire rotating assembly(flywheel and Fluid damper inclusive)balanced.

Dan

Dan,
This info should not matter if you are having the motor balanced, even though if the 427 pistons are a bunch heavier than the 396 ones were, you may have to actually add metal to get the crank balanced properly. The main reason I replied though was make sure your shop knows not to have the Fluid Damper installed on the crank when they balance it. The weight moving around in the inner ring will cause very erroneous readings on the balancer. This is true with all Fluid Dampers. You can take the Damper apart and put the hub only on the crank, but it really is not neccesary as the hubs are very precisely balanced from the factory. I am certain that the Fluid Damper instructions mention this, and any shop that does any amount of performance balance work should also be aware of it but better safe than sorry. Before someone else asks this, when using the 454 or 400 fluid balancers, you have to have the hub on the crank but never the actual damper part of the assembly.

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Bill Koustenis
Advanced Automotive Machine
Waldorf Md

Hey Bill,

Thanks for the info. Saves me hauling a fairly expensive and heavy part around to the shop. Also, appreciate your insight(s) which you have shared with me as well as all the other patrons of Team Chevelle.