6 sp flywheel questions
The rotating assembly was balanced as one unit. The shop that balanced it needed to add mallory at the front counterweight of the crank, and offset it at the balancer (it was drilled to remove weight). The flexplate had to be weighted because where the shop needed to add weight at the rear of the crank, it would have been too far forward at the rear counterweight, so it was added to the flexplate. The original flexplate setup iirc (I don't have the invoice for it in front of me) is an internally balanced (399174) unit (the part number should be on the flexplate next to or on the SFI certification sticker). It's $75 for me to have a flywheel or flexplate matched for the balance. Just bring the shop the one that's on the motor right now and the new flywheel.
right but building a 383 your changin everything obviously...........so it would be very dumb to externally balance the motor......
So anyway, now I got somebody to balance my flywheel, back to my other question. Is there any performance advantage to running a lightweight aluminum (13lb) to a stock flywheel (20lb)? I know it will rev faster, and obviously lose some weight which is always good. Not sure if it's a waste of $$ though if all it does is change the way I drive the car. There is also chromoly flywheels that weigh about the same as stock...does anybody see any issues running a stock flywheel at this hp level (420whp)? Clutch is a RAM HD with less than 2000 miles on it.
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if you autox the car than a lightweight FW will be a advantage under those conditions. Street and drag racing no.
SFI chromoly FW are good but with that said the stock FW (nodular iron) will work. If you are doing 6k clutch dumps with a tire I would get the SFI chromoly one.
SFI chromoly FW are good but with that said the stock FW (nodular iron) will work. If you are doing 6k clutch dumps with a tire I would get the SFI chromoly one.
Thanks for the clarification...I'll probably just stick with stock then because all these little odds and ends on this 383 build are adding up quickly; injectors, new msd opti, electric WP, tune, ect...I certainly won't be doing any 6K clutch drops with my 10 bolt out back
Maybe in due time I'll upgrade it when I have a rear end to handle the power.
Maybe in due time I'll upgrade it when I have a rear end to handle the power. 
The rotating assembly was balanced as one unit. The shop that balanced it needed to add mallory at the front counterweight of the crank, and offset it at the balancer (it was drilled to remove weight). The flexplate had to be weighted because where the shop needed to add weight at the rear of the crank, it would have been too far forward at the rear counterweight, so it was added to the flexplate. The original flexplate setup iirc (I don't have the invoice for it in front of me) is an internally balanced (399174) unit (the part number should be on the flexplate next to or on the SFI certification sticker). It's $75 for me to have a flywheel or flexplate matched for the balance. Just bring the shop the one that's on the motor right now and the new flywheel.
Or can I take both the POS Professional products crank hub and balancer off and go back to stock 
