i just got this truck and i am not too familial with this motor. I believe it is a 351w calif. model. my problem is I am not sure of the firing order. I am looking in a hayes manual and it states that the order is counterclockwise 1-3-7-2-6-5-4-8. My distibutor has a #1 on it and I am assuming that it is for the #1 plug wire? All the plug wires are in the correct order but the truck is gutless and backfiring please help!!

 

Are you sure that you have a 351W? The 302 and 351w look a lot a like. the 302 firring order is 1-5-4-2-6-3-7-8.
you are correct the 351W and the 302HO firring order is 1-3-7-2-6-5-4-8.
if you have the wrong firring order the engine will run but will have almost no power and will back fire a lot.

I would recomend doing a compression check to give you a better feel for the condition of the valves and rings.

Good Luck.

 

jpourner is correct. Try the other firing order if you want to.
Or if you want just measure the width of the intake on your engine and compare it to a car/truck that you know has a 302 in it. If yours measures the same then you have a 302 or 289 (the 289 has the 302 firing order). If yours measures about 3/4 inch wider then you have a 351w.

 

If it's a California truck it's a good chance the ignition is EEC-III (brown grommet on ignition module.)

The EEC-III distributor rotor fires alternately from both sides of the distributor rotor.

The firing order you listed is correct for a 351w, but the spark plug wires for an EEC-III distributor will be wired counter clock-wise in a different order.

351w firing order, CCW: 1-3-7-2-6-5-4-8

351w wire order, CCW: 1-5-7-8-6-3-4-2

Similar for the 302:

302 firing order, CCW: 1-5-4-2-6-3-7-8

302 wire order, CCW: 1-3-4-8-6-5-7-2

 

HEY! I remeber seeing one of those darn distributors now! That's a pretty funky setup. My dad had a 84 ford f150 4wd that had that distributor. The ECM went out and they wanted like $80 for it at the parts store so I swapped him in a regular distributor with matching ECM box and did away with that P.O.S.! Now if the box ever goes bad it's only $20 or so.

Huckermat....keep that in mind if anything ever goes wrong with that system just toss it and swap in a non-california type distr. and ECM box.