I know there's a member here that had a set for a 351M/400. They were used. He offered them to me, but I don't think I'll be able to pick them up any time soon. I believe his username is jnkyrd1 or something along those lines. Shoot him a PM, he doesn't get on here much.
By all means man, have at them. As long as somebody gets use out of them, that's all that matters. Shoot, I'd damn near spend in gas what a new set would cost to go get them...haha.