I'm putting together my 350, sm465 and noticed that I'm missing the bottom cover plate to keep out the gook. Its the peice that fits on the lower half of the bellhousing. Whats this peice called, I've been to the local junkyard and all they do is scratch their heads(keep in mind, you hear banjos in the backround). Can I order this peice from a gm dealer or do I have to go the junkyard route? Thanks