I have a 1969 buick skylark that i am transplanting a Buick 455 out of a 1970 wildcat into it.I am wondering about motormounts. The skylark origialy had a 350 in it. Do i need adapters?

Welcome to AF, I don't think so, the mounts from the 350 should fit the 455, not positive here though.

350 Mounts Wont Work.u Can Get A Set From Ta Performance,they're Online.the 400/430/455 Buicks All Have The Same Block.find Parts From A 400/430 Car From That Era 68-69 Get The Mounts.