There are NO off-the-shelf headers with that size that will work with a 351w in a stock Maverick chassis. I had to make my own. Some have said that the Hooker 6901's work, but they had to be modified to fit. 302 headers won't work either. Tried that already.
Tubular Automotive makes a set...1 1/2" primary tubes, but they're the ONLY ones that I know of that actually "fit"
I already have 1 1/2 in headers. I need some for my new motor. Its a 408w with 13 to 1 comp. Victor jr heads. Gonna shift around 6200 or 6400. What size you think would work? I may have to use the one's i have till i can get a set made.