Stan Johnson of FPA is currenly prototyping a set of headers for the FE series engines. I did the first install in late July and the passenger side was fine, the driver's side went in just fine but the collector was too close to the rack boot. Stan is now rehashing the header. The next set we want to do is for the 429-460 engines. I do not know the style of headers you bought from FPA, are they shorty's or tri-y style? If they are tri-y's you will definately need to modify them. All front sump engines and factory manifolds will clear the rack with room to spare.