The #1 issue is there is no 351 CLEVELAND engine. Of course 73 Mustangs also came with six cylinders and 302's. You could use the kit 289/302/351W. Then there is the incorrect exhaust system that should have one or two oval style mufflers. I could go on about there not being shock tower braces, a radiator shroud, no stock air cleaner, but you get the idea. If you want to build a shelf kit and glue the hood shut that can be done after filling in those incorrect hood vents. Otherwise, there are a lot of mods needed to make the kit something close to being accurate. Ram air plenum - forget about it or scratch build one.