how can u tell what u got?
Supreme Member
Joined: Sep 2001
Posts: 6,111
Likes: 53
From: Ontario, Canada
Car: 1988 Firebird S/E
Engine: 406Ci Vortec SBC
Transmission: TH-350/3500stall
Axle/Gears: 7.5" Auburn 4.10 Posi-Traction
Look at the harmonic balancer and the flex plate.
A 383 is built with a 400SB crankshaft which is externaly balanced. There will be a weight attached to the flexplate and a balance weight cast into the balancer.
A 350crank does not have these external balancing weights.
A 383 is built with a 400SB crankshaft which is externaly balanced. There will be a weight attached to the flexplate and a balance weight cast into the balancer.
A 350crank does not have these external balancing weights.