I was told to try posting about this swap here to get a quicker response. So I'll repeat myself a little here. I currently have a 95 F150 with the 5.0 Maf motor. I will be picking up a 5.8 from a 94 F250 hopefully tomorrow. If everything appears to be alright with the motor I am considering directly swapping the motor in. I've been doing some research on the questions I have but would like some reassurance. Here they are:

The 5.8 is not a maf motor, but since my truck is already setup with a maf system do I need to change anything? My confusion here lies with needing the complete engine wire harness from the 5.8.

The F250 was an auto, and I made sure I was getting the flex plate as well. I will have to call and see if they will include the y pipe. I have to call them tomorrow anyway to make sure they know I need the complete engine harness intact. Am I missing anything?

 

To my understanding if you have maf it has the same firing order, it should bolt right in and up, as long as you have the 351 with the EFI intake, fuel rail, injectors, distributor, it should bolt right in and up, the deck height is taller so your exhaust won't bolt right up though. good luck with the swap!

 

You don't need or want any wiring from the donor vehicle, just unplug everything at the sensors/actuators on the 5.0 and plug it all back into the same devices on the 5.8. You need a complete 5.8 EFI motor for this swap, that is everything from the oilpan to the throttlebody and including the distributor and exhaust manifolds. You will also have to widen the Y pipe or install a 5.8 specific Y pipe, and make sure you get the right flexplate for a 5.8 and whatever transmission you have, do not assume they are the same. The trans code appears on the decal on the drivers door pillar, U is 4R70W, E is E4OD, T is AOD. The AOD and 4R70w use the same flexplate but the E4OD is different and this flexplate cannot be used on the other transmissions.

 

Thanks for the help guys.

I have the complete 5.8 efi motor, oilpan to throttlebody. Being a junkyard motor, they had cut the catalytic converters off before I ever looked at the motor, so the y pipe was trashed. I am looking at long tube headers for the motor so i will have to fab something up anyway. I'll have to go back to the yard now knowing the codes to see if the flex plate is the one I need.

I decided to rebuild the motor before swapping it in for the 5.0. So I will have some down time, but the swap itself seems like it will be straight forward. I found a set of remanufactured gt 40 heads that may make it on to the rebuilt motor. I can still use the same intake for this right? This is a second vehicle, but its main intentions are for the street, so it won't be an extreme rebuild. Are there any other recommended parts to go along with this setup? And will the 5.0's computer still be capable of running this?

 

the knock sensor you have to over ride, or install it into the 351, but the computer will work yes. I'm not exactly sure how to over ride it, but hear its a resistor you can find on ebay

 

Yeah that's right the 5.8 doesn't have a knock sensor, but it can simply be left disconnected I never has any problems doing this. If you want to really unleash the motor's potential swap in the Comp cams 35-320-8, combined with those heads and an exhaust system you'll have a ton more power than the 5.0 could ever hope to generate. I'd also suggest you get out the carbide bit and open up the port exits in the lower intake to better match the heads, that is a choke point in this intake system.

 

That cam says it is designed to run with 1.7 roller rockers and for the 5.0. I'm assuming the cam is interchangeable. Would I have a comparable build with this cam and the 1.7 roller rockers on the stock heads? This is somewhat of a budget build and am trying to figure out where I can spend the money. Or will the cam/gt40 head combination on stock rockers be sufficient.

This has kinda been something I have blown off and will only really know once its up and running, but I currently get about 12 mpg mostly city driving with the 5.0. Can I expect the same with the 5.8L? I know the biggest contributor will be how I drive it. I just don't want to do all this and then I'm running single digits for mileage. It's a 4x4 supercab, 3.55 gears, 31in tires

 

with my gears,tires and motor goodies i see 10mpg city and 14-15hwy. granted i am still running the E7 heads and stock cam. but i do have the eddy efi intake, jba headers and custom exhaust on a fresh 357 build.

 

Ignore what Summit racing says about the cam it will work just fine with 1.6 rockers, and yes all Windsor family motors use the same cams.

I don't recommend using 1.7 rockers with this cam on either the stock or GT40 heads, they generate too much lift for the stock valve springs and won't add any performance so there's no point spending the money. With stock heads the motor won't make as much power but it will still be quite a bit stronger than the 5.0.

I have the same truck and with a similarly equipped 5.8 it got 13city and close to 18mph highway cruising at 70mph on mostly flat roads.

 

Block is finally back from the machine shop. Crank is back in and plan to get the pistons and rods installed this weekend. The block needed to be decked, and was bored .030 over. The set of GT-40 heads I ordered will be in sometime next week. I can't wait to get this thing up and running...

The machinist seems doubtful on the cam suggested above, but I'm thinking he is looking at the amount of valve lift with the 1.7.rr. If I keep the stock rockers, or go with a set of 1.6rr, i figure the lift should be right at .512. Still above the .500 max on the heads, but will this really be enough to be worried about? He also feels that stock springs won't handle this came. I think that is related to the 1.7 rockers as well?

 

I have the sister cam in my 5.0 right now with stock valve springs, 0.512" lift and no coil bind(yes I checked) or any valvetrain noise whatsoever, and the motor makes a ton more power than stock.

 

Heads are on, and cam is in. Ran into a small problem with pushrods. Looks like I need longer ones. Does this sound right? I ordered a tool to measure the length, and if I'm reading it right I need a set at 7.575. Haven't started calling around yet to see if anyone has anything close.

 

Your block was decked so you will likely need custom pushrods but that is a lot shorter than stock (8.2"). What method are you using to determine the length?

 

I'm using a push rod length tool from comp cams. Starts at 7.5" and every full revolution is an extra .050". I came up with 7.5 plus 1.25 revolutions, to give me 7.5625. My numbers from the earlier post are wrong, due to a miscalculation.

Called comp cams and they are sending me a set at 7.6". My measurements were made with just the tool being snug. The technician said there should actually be some preload on the rockers, which would add an extra .030". Which sounds like they will be very close if thats the case. If not I may have to shim the rockers a bit.

From what I have seen so far, looking for replacements, there are two different length factory pushrods. I could be wrong here, but I have seen the 8.2 and a 7.54, or something close to that. The rods that came out of the block are measuring 7.5 using a tape measure, which isn't very accurate.

 

With the help of a machine shop I think we figured out why I needed custom length pushrods. The newly rebuilt heads have valve stems that were ground to a different length. This was found after finally finding a set of rods that worked on cylinder one, and then cylinder 5 had both valves open. Machine shop saw .010 - .015 variation between the valves, and they are .040 shorter than required.

Anyone have some good information on heads? Looks like I'll be replacing valves as soon as I find the right set.