So need some help. I have a 1994 f150 with a 302 with the 4R70W U type tranny in it and I’m planning on swapping motors, I have a 351 engine that I wanna drop in and have been reading some forums on this swap but i can’t find 100% answers. Wondering if i can use the same tranny, computer and driveshaft or if they need to be replaced. Everywhere i have read has said both yes and no. Any help would be great. What flexplate, distributor and things like that I would need. Making it carb. Thanks

 

Start your own thread instead of tacking onto a stale one.

The correct answer is you can use the existing pieces already in the truck.


You need a flexplate for a 5.8L engine with an AOD transmission. Crown Vic's have this combination.


Why make this swap that much harder for very little to no gain other than a thinner wallet?

 

Couple of questions for you. Why do you want to downgrade to a carburetor and the other is how do you plan on controlling that electronically controlled transmission?

 

My 95 is a 5.0 manual with map and I'm wanting to swap a 95 351w into it is this still as straight forward. Debating on whether or not I want to swap my 5.0 out or just put a different one into it

 

you can do a 351, but you need to find a 351 5 speed computer to run it. Look for f250s and 350s of the same year. You will also need all the 351 fuel injection manifold and fuel rails

 

This is still a good swap, a 5.8 is almost a direct bolt in and it is a much better truck motor. No wiring changes are necessary and it is advised to not use ANY wiring that comes with the donor motor, strip all wiring from the donor and connect the 5.0 engine harness directly to the sensors and actuators on the 5.8. A different flywheel is needed and the exhaust system will need a small modification to fit the wider 5.8. The 5.0 computer will run a 5.8 but probably not to it's full potential, the two motors use all the same sensors, same injectors and heads so fueling requirements aren't a lot different.

 

Ive always been under the impression a 5.0 SD computer wouldn't run a 5.8?

 

Yes the motor will fire up and run, why wouldn't it.

 

I'm planning on just buying the complete engine so it will come with the fuel injection stuff and fuel rails will probably try to get him to throw the manifold in also 🤞🏼 as far as flywheel goes will have to do anything with that aspect or my starter? was told my flywheel and starter wouldn't work with the 351

 

Well yeah, but as for driving i didnt know if a SD system would adjust for the 14% extra displacement. I figured maf could do it easy since it reads the airflow into the engine.

 

I'm not sure, but more than likely the SD will be fine. A tuner would be better, or EEC for the correct displacement of engine.

I took a plain stock 351w and put a lightning tune in it, same displacement, but obviously fuel, spark, injector tables completely different. Truck would randomly backfire. I ended up putting stock tune back in.

Sure it'll run, but not optimally, and any other mods should have a tune done.

 

Yes MAF does it for sure, but even SD has some room to work. So yes, 14% greater displacement which will require a little more fuel but that is well within what the injectors can supply(25% more), I don't recall the exact number but I think there is + - 15% adjustment range available in the fuel maps and in closed loop the computer will see a lean condition at the O2 and make adjustments. In open loop there is no feedback so there is potential for problems there but the open loop fuel map is richer than closed loop to begin with so maybe not that bad. For heavy duty use the correct PCM would be advised obviously, but it's not absolutely necessary to make it start up and drive around.