I'm not familiar with the Roush heads but if they use the same bolt configuration as the others (Ford/World/TFS/AFR/Edelbrock/Etc.) then you can use just about any header there is. If you have an early model (65-66) then you'll need specialized swap headers but the later cars (67-73) can use just about any. I have Hedmann Elites on my 351W/AOD combo and there's TONS of room in the 67 chassis, ground clearance is also quite good.