I just installed a set of the "Summit House Brand" headers in my '68 F100 shortbed (originally a 6cyl/3pd, but now a 302/C4 converted with '73 mounts). I had to lift the engine out of the chassis about 3 inches to get the headers into the chassis and bolted up to the motor (i had to have the starter off to get them in the chassis and then snake it in and bolt it on before I could bolt up the headers). When I went to lower the motor, both collectors hit the crossmember that goes between the radius arm mounts and wouldn't even let the motor sit down on the mounts. I had to take the headers back off, pull the engine and trans back out, and I had to cut clearance notches in the crossmember and then box them in with 1/8" plate. I didn't like having to do this extra work, but I am very pleased with how it came out. After I went through the engine/headers/starter installation process for the second time, everything fit perfectly and the notches I made are unnoticeable unless you crawl up under the truck with a droplight. I am in the process of running the exhaust now. Now that the headers clear the radius arm mount crossmember, they are aimed directly at the trans crossmember. Luckily there was enough room that I could put a soft S-curve pipe from the collector reducers that curved up and over the trans crossmember. I am using 2 1/4" pipe and I have sufficient clearance between the trans crossmember and the floorpan (albeit more on the passenger side than the drivers side). I'll post a follow up as I continue.

chris seay
bealeton, VA
49 F1s
68 F100

 

Sounds like you got the header headaches! Glad to see you got them in and thanks for posting so future users will be able to not make the same mistakes. Excellent post!