I know that this should go in the engine forum, but I do have a post there and I'm getting a lot of coulds and maybes. I would like a little more definite answers than that.

95 F150 302, 4R70W 4x4.

I am thinking of doing a 351W swap. I'm told that this trans will bolt to the 351W, but would not last with it's power. The trans was rebuilt about 20k miles ago and no problems. What do you think?

Also, I need to know about computer. I'm told the 302 computer will work but may need to be reprogrammed. I thought that I would need a computer for the 351W but seems that that motor never came with the 4R70W. What are my options?

Maybe this swap wouldn't be so easy. Alot of people on this board seem to think that this is the ultimate and easy swap. I'm doing a little research beforehand and am running into problems. Anyone else do this swap and could you give me some pointers.

Thanks
Al

 

I would stroke that 302 to a 347 and save a lot of swap trouble!

 

Yeah, I'm coming to that conclusion as well. Hard to get definite answers and is looking as though this tranny is not optimal. I don't have a problem with the 302 as of yet, just looking for options down the road. Would like more power to tow our travel trailer.

 

I'm assuming it's a Mass air vehicle.

In that case, check the code of the computer and find out if the computer is compatible with SCT tuning chips, Tweecers, etc (tuning software).

It should run a 351 just fine...the MAF should adjust for the extra CI but I bet many people may of got that confused with speed density, where you'd need the 351 computer.

 

If you're swapping a complete engine, with EFI, sensors and such, it's almost a bolt-in. Swap motor mounts, swap engine, plug engine harness into body harness, swap EEC's from 302 to 351W.

All junkyard or ebay items.

The thing to pay attention to is if your truck is mass air, then you need to swap in a mass air 351W for minimal hassles. If your truck is speed density, then a 351W speed density EFI setup makes it easier.

It's when you cross from one to the other, that you have some wiring and sensor changes to make. All doable of course, just takes more time and a bit more effort in getting things right the first time.

 

Fred, whats a mass air engine??? any efi 5.8 will work in this situation. if his current setup is mass air with the 302 he can keep the harness and ecu from that combo and run the 5.8 just fine. the current harness will connect to everything on the 5.8 just fine. he actually has the best setup possible for this swap , i would be curious about the tranny being what is stated, are you sure its not an E4OD? i know the 4r70w were in some 2wd applications and didnt hit the 4wd's except in the exploders. reason i ask is making sure we get the proper flexplate to work in this situation

 

I believe it is the 4r70w. I think that was available with the MAF/95/302/automatics...

 

mass air and speed density engines are the same, it's the EFI bits that are different - EEC, wiring, sensors, and other dodads.

Because the 302 and 351 wiring harnesses are the same, swapping in an engine with the same type of Ford EFI as the original, makes the swap that much easier.

That's all I was saying. Mechnically, the engines are essentially the same minus a few piston top differences to change compression ratios, as well as the cross hatch pattern in the blocks changing in 95. Irrelevent for this discussion.

A mass air EEC for a 302 will run a 351 fine, to about 4500 RPM then it will not be very happy.

 

It is mass air. It has one tube out of airbox and splits to two for the throttle body. There is a electrical connection and sensor right there at the airbox.
My main concern for this swap is using the 4r70w. The door code is a "U" and is the original trans.
Frederic, you said swap eec from 302 to 351w. Are you saying to use a 351w eec? Will a 351w computer work with the 4r70w instead of the e4od?
Thanks for the replies.
Al

 

My bad.

I forgot the 4R70W is related to the AODE, both of which are electronically controlled transmissions. I do not believe the 4R70W came behind the 351W, as the 4R70W would break apart from the torque if the truck is loaded heavily. I called a buddy of mine who has the Ford dealer service manuals fr the 95 model year, as his F250 and Taurus are both 95's. Anyway, since this combination doesn't exist from the factory best I can tell, sending you on a wild goose chase is rather silly.

So I will fall back to Justin's comments where he suggested you use the 302 computer, and tweak the settings in the EEC to the larger engine, unless of course you're not planning on hitting 4500 RPM, in which case there's enough range in the tables where it will run the 351W fairly well. The problem lies with the maf sensor mappings for the 302 - doesn't take into consideration the extra 49 cubes of the 351W. At lower RPMs this isn't an issue because the EEC will use the O2 sensor, but if you full throttle the truck the o2 sensors are generally ignored so ... that's when things will run really lean.

I'll make a call to my local ford dealer and confirm that the 4R70W was not available in the F250/350 for the 95 model year... which are the trucks you'll find a 351W.