On my 74 F350, with a 390 and NP435 4 speed, I had a set of Hedmans for 15 years, and then a pair of FlowTechs. Both fit very well, and performance and gas mileage both improved noticeably. Best of all, I was finally finished with replacing cracked factory exhaust manifolds. I find the FlowTechs are great headers for the price. I also have a pair of 1 5/8" long tube FlowTechs on my low 10 second 331 SB Ford bracket car, and had another pair on my 85 Mustang, for the money, you can`t beat them. On a FE truck, to replace the starter motor, the pass. header needs to be removed, or maybe loosened and pulled away, but I think most FE headers are that way.