These are out of a 99 STS with 4.6 Northstar engine. I had the heads resurfaced and vacuum tested at my local machine shop. However these are not compatible with my 2000 Deville. So here they are. Asking 250.00 + shipping for the pair. I wouldn't imagine it more than 100.00 for freight but I'm guessing. I can provide a firm price once contact by a serious buyer with zip info.