klassikalgas

Picked up a '87 GT that doesn't have the engine it was born with.
Few pieces missing--distributor is one of them.
Think the firing order is different between a 5.0 and a 5.0HO
How can I figure out what engine I have?
Thanks

pure_kaos

Easy way to figure out is HO have E7 heads, non HO use the E6 heads, the HO upper intake and throttle body opening 58mm and non ho 50mm. Pop off one of the valve covers and see if E7 or E6 is stamped inside. And yes you are correct the firing order is different.
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imp

Easier: Check plug wires, starting with #1: non-HO firing order 1-5-4-2-6-3-7-8, follow wires around dist. cap., counterclockwise starting at #1.

08'MustangDude

Do you have that on your intake?

wbrockstar

If the present engine has all of the parts it came with from the factory and the parts on the engine are Non HO parts,then you can tell if its a Non HO,but if someone has added HO parts to a Non HO engine,it would be hard to tell.Most Non HO engines were unpowered too,150hp vs 225hp.If someone takes a Non HO engine and drops a HO camshaft,ecu,injectors, heads & intake in place,it is now considered an HO.HO came with 13726548 firing order & 15426378 for the Non HO.The firing order (cam) ecu and injectors are the main components that would have to be changed for it to run similar to a HO.A Non HO cam & injectors wont work with a HO ecu and vice versa.