I have a 1967 mustang, and when I bought it I was told that it had a 302 in it. I was told that the 302 came out of a 1971truck. I have been recently tuning up the carb, timing, etc., and have noticed that the current wiring of the distributor is for the firing order for a 351. I thought that this was probably not right so I wired it for the firing order for a 302. The engine would not run unless at high rpms. I switched back to the 351 firing order and was able to adjust the timing and now the engine is running great. But I am confused, why does my "302" only run with the firing order for a 351? How can I confirm what engine is really in the car. I can't seem to find any casting marks on the engine. Is there any reason that a 302 should be run with the firing order for a 351?

Thanks,
Larry

 

someone might have installed a cam with the 351 firing order or you have a late model motor from a mustang or a lincoln mark 7,tbird etc

 

An easy way to distinguish the 351W from the 302W is the deck height.

When you look at the front of a 302, you will notice that the heads look like they sit directly on top of the front timing cover.

The distance between the timing cover and the bottom of the head for a 351 will be about 1 inch.

Also, on the front of the intake manifold, behind the distributor, there will be a bit of a step on the 351 whereas the 302 is straight up and down with no step.

If it is in fact a 302 running with a 351W timing order, then somebody put a 351 cam into it.

Just as an aside, this isalso the easy way to distinguish between a Pontiac 350 vs. a 400 or 455. That and the engine size is cast into the bottom of the Pontiac block.

 

in 82 Ford started using the 351 Marine cam in GT's and the roller cams (85 and later) are also the 351 firing order. It could be a later model cam/motor or 351 cam as others have said. The width will give away the 351 as fastbackford351 has stated.
Craig

 

IIRC.... Yes the "newer" 302s share the 351 firing order. That's a good thing. The original firing order had two side by side plugs going off in sequence. Sometimes you could get electrical "bleed over" that caused a plug to fire at the wrong time, which is never a good thing. The revised firing order fixes that problem.

 

Fastbackford351 thanksfor the info about the size differenences between 302 and 351. Does anyone know where I should look for the casting numbers on the engine to determine what type it is? The engine is mighty dirty and probably needs cleaning at the right spot for me to see the casting numbers. I have a book which tells me what the casting numbers mean but I don't know where on the engine the numbers should be.

 

Now that I did not know. Welp, I won't go to sleep tonight quite as ignorant as I was when I woke up this morning. Mission accomplished for the day.

 

fieg, the block casting number will either be on the passenger side near where the starter sits, or on one of the "ears" of the back of the block near the bottom where the lowest bellhousing bolts attach

 

What do you mean "what type it is"? The casting numbers are on the bottom of the block under the starter. Not one of Fords "Better Ideas"

 

Considering both firing orders have a cylinder right beside the other such as the 6 and 5 on the 351 and the 7 and 8 on 302 and so on, That has to be the dumbest thing i ever heard.