Remember that the 400 is externally balanced, so it's a damper AND part of the crank balancing (which also includes the flywheel/flexplate). I don't think stock replacements cost that much...just make sure you get the right one.
Edit: Summit Racing $62.95 on up.
cm
THIS!!! I ran in to this issue with another car. for the life of me could not figure out the issue until it was pointed out tht the crank was not internally balanced and the balancer i bought was for an internally balanced crank.
