FYI FORD MustangSteve's Ford Mustang Forum / 351W header problem

**Posted by ps77sb** 1/04/2019 11:34 PM

Its been awhile since I posted. I wish I was better at this. A while back I inquired about header for 351W in a 1977 F100 (original owner). It was suggested to use 1980 to 86 with that engine. Not even close. In 88 when I installed the 351W I used 302 hdrs. Had to bend the pass side to clear starter. Now years later and a new engine with dart II heads # 5 spark plug is aginst the header. I'll have to reroute the pipe or buy a 3/8" hdr flange and install it between the header flange and the head. As always thanks. Really enjoy this board.
Huh hell pay attention.
'

**Posted by rpm** 1/05/2019 11:39 AM

Don't be scared.

**Posted by Ron68** 1/05/2019 2:49 PM

I would think that there would be lots of room in an F-100 with that motor for headers. I have a 351W with 5.0L heads installed in a 68 Mustang with a 4R70W transmission. I found that a set of JBA shorty headers fit very well, with no spark plug issues. I did have to cut off a small protrusion at the front driver's side of the block (76 block) to clear, but otherwise, a great fit. I believe MS used the same headers in his 66.

Last edited by Ron68 (1/05/2019 2:51 PM)

**Posted by ps77sb** 1/05/2019 4:02 PM

The engine that came out of the truck had mid 80's 5.0 heads. The 302 headers bolted on but had to be bent down on passenger side to clear the bell housing. the trans is a T/L 4 speed replacing the OEM 3sp. the engine that came out and the one installed both have a threaded hole for the bell crank to pivit. The DART II heads on the new engine apparently relocated the spark plug closer to the center of the combustion chamber. 1977 F100 T/L 4sp 351W 9" 3.50 TL

**Posted by Brents65** 1/05/2019 8:24 PM

Did you try the shorter header spark Plugs? That should help clear the tube.