Hello everyone this is my first post on this website. I need to know if my engine is a 351w or a 302. I have an 86 f150 (partially, mostly f350) and the original engine was a 302 but the guy I bought the truck off of said he put a 351w in it. Here is the block casting number: e4ae-6015 and then It says fa-19. I know it is an 84 block but don't know how to tell if it is a real 351w.

 

Welcome to FTE.

There is some help for your particular questions here in the Sticky:

Ford Truck Enthusiasts Forums - View Single Post - '80-'86 Tech Tips, Tricks and Projects:

 

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You can also look at the spark plug wires. 302 firing order is 15426378. That means the 2 plugs closest to the firewall on the drivers side will be two spark plug wires right beside each other at the distributor cap ( a common problem with 302's as the 2 cylinders fire one behind the other and it's easy for the plug wires to 'leak' and fire between one another...just fyi). 351 firing order is 18436572 so number 7 & 8 spark plug wires are not one behind the other like a 302.

 

302 HO motors use the 351 firing order.

Non HO 302's use the old 289 firing order.

 

Also aftermarket cams can use either the 302 or 351w firing order, and they both interchange in either engine.