Hello! I'm currently restoring a friends 77 f150 and i ran into a problem with the headers i ordered. I went to bolt them on and the drivers side hits the 4x4 housing. i later found out that the truck had a 400 not a 351w. looked at the directions and they say that they will fit a 400 also. they say that it will fit 4x4 and 2 wheel drive models. so in theory these headers should fit. now the instructions say i may need to lower the froth axle and attach headers and then re attach the front axle etc. Is this true? is there a better way? possibly shorty headers? sounds like alot of headache and i have been pushing this truck in and out of my garage daily to do body work in the sun and it is frustrating when the truck has a brand new motor i cant start due to no exhaust. any advice is appreciated thanks. BTW the headers are flow tech. I know there cheap but so is the guy footing the bill.