MP Frame Connectors

Not really a mistake. You can bolt them in and then take them in to be welded later, just means a little more effort to prep the weld area. As to a porus weld, if whoever does the welding knows his stuff, he'll be able to get the pieces welded together just fine, oil in the weld is a bigger concern than a little oxide of iron. I am/was a welder by trade and am very anal about weld prep, but know that sometimes your just going to have to deal with a little crap in the joint your trying to make. It just depends on what the purpose of the weld joint is as to how crittical it will be. Sub frame connectors are not what I consider critical. A mediocre weld will hold them in and allow them to do their job.