Trying to cover all my bases here. I haven't given up on headers yet, but just in case I can't find any that work without spending a fortune, will these work on my 72 351C 2V in a 68 Mustang? Are they essentially the same as the 70-73 Mustang manifolds, or are there major differences. The RH manifold I have is D7TE-9430-AB and the LH is D5AE-9431-AB. Anyone have any info as to what these came off of and if they'll work for me?