How to tell the difference between a 302 and a 351?

We are parting out an 84 F150. The seller claimed that it had a 351 but we believe that it has a 302. How to tell the difference?

A 351 is taller, the distributor hole is ~1/2" below the intake gasket surface.

the 351W has a 1-3-7-2-6-5-4-8 firing order versus the 1-5-4-2-6-3-7-8 found in the 289/302.

wclark wrote: the 351W has a 1-3-7-2-6-5-4-8 firing order versus the 1-5-4-2-6-3-7-8 found in the 289/302.

That firing order should be cast into the top of the intake manifold.

302 is much narrower, 18" across exhaust manifolds IIRC. Intake is much smaller than a 351.

302 Block. Note distributor hole.

351 Block. Note sunken distributor hole.

also, as seen above, the head deck height is higher up from where the water pump bolts up

NOHOME wrote: 302 Block. Note distributor hole. 351 Block. Note sunken distributor hole.

Thanks, I've never noticed that before.

The firing order can vary based on what cam is in the engine so don't count on what is cast into the intake. If someone changed the cam... who knows?

NOHOME had it, look at the blocks, an easy determination using those pictures.

The water pump deck height is the easy way to tell. If the head is sitting on top of the water pump its a 302 or 289...or 260.

Thank you very much. You folks rock!