SBC 400 flywheel

[leesr]

heres the deal, I have a std 168 T flywheel that was drilled & converted to a
383 stroker external balance by a previous owner.
I was replacing my clutch, Took my flywheel & pressure plate to have it balanced at a machine shop. and they FBAR my flywheel.
shop said it was out 76 grams, they added heavy metal now it's out of balanced. vibrates like hell. Never asked me for permission to do this.

I would like to know what the unbalanced weight is for a standard flywheel & a matching damper for a 383 stroker crankshaft externally balanced .

My crankshaft is of two piece seal design. I will be dropping the oil pan to see the crank serial# & make sure it's not internally balanced.

[RacerRick]

I hope you mean a 2 piece rear main seal and not a 2 piece crankshaft!

[leesr]

Yep thanks corrected my mistake.

have I hit a dead end here?
I was hoping some one has run into this before.

Part of my problem is if I purchase a new fly wheel I have to also buy a new clutch.
the stock SBC 400 External Balanced flywheel takes 11" clutch.
my retrofit flywheel had a 10.5" clutch

[1972L]

McLeod had some on Ebay for $200
They were Aluminum
They were factory closeouts
and dual drilled for both clutch sizes

I think the factory SBC external balance weight is 44 grams on a 400

[leesr]

an other balancing shop put an external weight on a scale.
I was told "125 Grams"

found a Mcleod brochure

125.5 grams is for 1986-97 GM 1 piece seal Crank SBC 305 350
156.1 grams is for 1970-1981 GM 2 piece Seal Crank SBC 400 383
210.5 grams is for 1970-90 GM Cranks 454

Go fiqure

[leesr]

see above comments

[1972L]

Mcleod has the "bolt on" external weights on some of their flywheels
I guess they would know better than anyone

[pdq67]

Please consider looking into what Northern Auto Parts sell's in the way of flywheels and flex plates.

pdq67