F250 302 to 302 H.0 swap

[fordforever225]

hey everyone new to the forum. I have a 1989 F250 4x4 5 speed manual (assuming its a light duty). I recently ran the truck out of oil on a long trip. the truck lost a lot of power (as if it had any to begin with, gutless wonder). im guessing there is atleast one burnt valve and or piston/ring. I recently purchased a clean 1986 5.0 ho motor from a friends mustang that was a rust victim. Ive done a bit of research but my findings are inconclusive. a close friend of mine is a professional mechanic willing to do the swap for $600. Can anyone tell me FROM EXPERIENCE what issues I may run into? What is the best route to go with truck vs mustang intake? will the headers from the truck bolt to the H.0 block? any info is greatly appreciated.

for the record the motor is complete with all accessories.

AND for the big shocker. should I sell it all and try to do a 7.3 swap?

 

[junkyardjeff]

If you retain the 89 EFI system you will have to change the wiring to the injectors to the way a 351 is since the HO uses a 351 firing order.

 

[5.0Flareside]

When I get to work later I'll post on lunch. Its pretty simple.

 

[5.0Flareside]

If you retain the 89 EFI system you will have to change the wiring to the injectors to the way a 351 is since the HO uses a 351 firing order.

No you will not. The batch firing of the speed density system is the same for both firing orders.

 

[O'Rattlecan]

I wouldn't worry about the fuel injection at all. Just make sure you use the distributor and firing order that the Mustang used, don't try to swap in your firing order from the truck. The 5.0 HO and 5.8 share a firing order.

This should be a fairly simple swap, however I'd use the upper intake plenum from the truck so it hooks up to all your air boxes properly. I'd also use the exhaust mainfolds (or headers) that the truck had.

Ryan

 

[1970Custom]

As to your last question, I'd say yes, IF you can find a complete donor, OR sell the truck and buy a diesel....

 

[5.0Flareside]

Sorry for delay. Busy day at work.

The swap is straight forward.

Take the mustang engine, (virtually same as truck except cam, intake, and certain years pistons).
Put the truck, timing cover, water pump, accessories, oil pan, intake, exhaust on the mustang engine.

You can still use truck distributor just have to use timing gear from mustang distributor (roller vs flat tappet) cause different materials.

Install engine with all the truck stuff on it. Wire the plug wires H.O./5.8 firing order.

Fire it up. Drive it.. Its that simple.

The speed density system uses a batch firing system for the fuel injectors. The batches are same for both the old 5.0 firing order vs the 5.8/H.O. order. No different.

 

[junkyardjeff]

How does this batch firing system for the injectors work,I was thinking about putting a 351 in place of the 302 in my 88 bronco and was told I would have to change the wiring for the injectors to match the firing order.

 

[Fellro]

Batch firing means that either all (or one bank) fire at the same time. These are not sequential fire, where the injector pulse matches the cylinder, they all are more of a "spray and pray" approach. As fast as the engine spins, there is such a short time before the valve does open that they can get away with such a method.

In basic, the wiring is the same, because they all tag together. Even sequential, the wiring isn't critical as the COMPUTER tells the injectors to fire. The only reason the wiring would matter is if the wires were arranged differently, which from a manufacturing standpoint is inefficient and wasteful. With a batch fire system, the wiring means nothing other than a string of injectors tied together to fire all at the same time.

For a 7.3 swap, you need to be relatively familiar with how they work and are wired to be able to pull it off without making your life difficult. Only good reasons to do a swap like that vs buy one already installed is if you 1) just want to, 2) REALLY like your truck and don't want to give it up.