walter34payton2002

Hey fellas. I had an interesting problem today. I went to change spark plugs to the OE Motocraft plugs listed for my 1985 f150 supercab, fi, 302. The gap for those is .044. When I pulled out the old Autolite and tried to put the new Motocraft in, it would not thread in at all because the thread was too large. I took them back along with the autolite I pulled and I traced it down to the 1986 Ford Mustang that uses that plug. The autolite was part 2545 and the motocraft was part SP501. Now the gap that the autolite and mustang say is .050. The Motocraft and f150 is .044. I found the autolite I pulled was gapped at .044. I guess my truck has Mustang heads????? Here is my questions...........

What could the explanation be other than this has mustang heads?
What other Fords use that plug? Maybe the heads are from something else?
What gap do you use- the one for the head you have or the one for the ignition system you have? I already installed them all and gapped them as f150 called for.
Any other info would be helpful. Thanks!!!

walter34payton2002

As I think about all this......Do I have a Mustang engine? Now how would I tell?

walter34payton2002

One more thought....If the Mustang has everything identical (as far as engine and ignition) then wouldn't I use the Mustang gap even if I have the f150 engine that could have mustang heads? I suppose that the older crown vics could have used the 302 as well? How can one tell?

Nitehawkjr

Is this the original engine? Ford went to the smaller plugs in the F150 302's in 86 i believe but the MC plug # should be a SP502 which is a 5/8" drive plug. I would gap them at .044

walter34payton2002

Here is the thing- I copied a list of Ford vehicles that uses the plug that fits my truck. Here is what Rock Auto has:

FORDAEROSTAR(1986 - 1987)FORDESCORT GL(1987 - 1988)FORDESCORT LX(1988 - 1990)FORDESCORT PONY(1987 - 1990)FORDLTD(1984 - 1986)FORDLTD BROUGHAM(1984 - 1986)FORDMUSTANG(1984 - 1997)FORDMUSTANG GT1986FORDMUSTANG L1984FORDMUSTANG LX(1985 - 1990)FORDRANGER(1983 - 1988)FORDRANGER SUPER(1986 - 1988)FORDTAURUS GL(1988 - 1995)FORDTAURUS L(1988 - 1992)FORDTAURUS LX(1988 - 1995)FORDTAURUS SE1995FORDTHUNDERBIRD(1984 - 1992)FORDTHUNDERBIRD LX(1987 - 1997)FORDTHUNDERBIRD SPORT(1987 - 1988)FORDWINDSTAR1995LINCOLNCONTINENTAL(1986 - 1990)LINCOLNCONTINENTAL EXECUTIVE(1991 - 1994)LINCOLNCONTINENTAL GIVENCHY1987LINCOLNCONTINENTAL SIGNATURE(1988 - 1994)LINCOLNMARK VII(1986 - 1987)LINCOLNMARK VII BILL BLASS1987LINCOLNMARK VII LSC1987LINCOLNTOWN CAR(1986 - 1990)LINCOLNTOWN CAR CARTIER(1987 - 1990)LINCOLNTOWN CAR SIGNATURE(1987 - 1990)LINCOLNTOWN CAR SIGNATURE SE1989MERCURYCAPRI(1984 - 1986)MERCURYCOUGAR(1984 - 1986)MERCURYCOUGAR LS(1987 - 1992)MERCURYCOUGAR XR-7(1987 - 1997)MERCURYGRAND MARQUIS(1986 - 1991)MERCURYLYNX(1986 - 1987)MERCURYMARQUIS(1984 - 1986)MERCURYMARQUIS BROUGHAM(1984 - 1986)MERCURYSABLE(1988 - 1995)

Nowhere is a truck on this list which tells me that I have to have at least heads from a car, right??? Any ideas how to tell what engine you have? Thanks.

94Bronc

find the code stamped on the block and do a search for that number

Nitehawkjr

As Bronc said do a search on the block code number if it checks out for a 85 do one on the head numbers to see what they are.

walter34payton2002

Exact location of numbers? Thanks.