your best bet is to run the lines foreward and aft on the frame rail from the frame mounted m.c. you can "adjust" your engine mounts as needed,but usually,run the lines low along the frame rail just in front of the crossmember, and you will miss the mount altogether! Then run on the backside of the crossmember and over to the pass.side. think about thru the frame fittings,as it will make your life easier,and makes a neater setup.You will have to either cut 2 access holes, one in each x-member to run the line to the front and rear. while your at it, you may want to think about cutting exhaust passages in the rear x-member, as it will make it alot easier to run exhaust, as you will be stuck trying to pass a pipe through the x-member close to the outer framerail, and trust me....it WILL rattle!! You will need to also cut an access hole in the rear pass.side x-member to run your gas line and battery cables! a small amount of time now,pays off BIG TIME later!!