Im building a 331 for my speed density 93 F 150. Stock 302 had a hydro roller with a 302 fire order. (very tiny camshaft). I have a HO cam with a 351 (1372) fire order. I was wanting to know if the Computer will recognize the new fire order over the old one. If it wont work what changes have to be made. Ie moving wires from injectors or changing pins on ECM. Anyone ever done something like this? Thanks

 

The EEC has nothing to do with the ignition. All it does is provide timing advance info thru the SPOUT circuit.

The firing order is determined by 2 things: camshaft & the order you put the wires on the distributor cap. If they match & you route the wires correctly, the engine will run right.

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Thanks for the info. I was pretty sure it would work. Thanks for verify.

 

Some comment on your conversion motor.
The camshaft; if it has timing duration that lowers the intake vacuum very far, may idle hunt and never be smoothe at idle.
The MAP and fuel curve is calibrated for the small displacement engine.
If you think your HP level will surpass about 280 hp, then the injector size could become a factor.
You may luck out but expect some problems along the way.
I would suggest you consider conversion to Mass Air and eliminate all these possible problems.
Good luck.

 

if you are wondering about the injectors firing at the wrong time, dont ..they bank fire on a SD truck anyway. and if you convert to mass air in a kit they will still bank fire unless you put in a new fuel injector wiring harness, or make one like i did(that was lots of fun )