I looked into putting an L motor into my 5.4L 1997 Expy.
I don't have all of the details, but stopped my quest when I discovered that:
- need to replace ECU as you mention
- need to replace wiring harness
- need to install electronic gauge cluster from newer model
Also, I'm not sure what tranny you have, but I believe the 4R100 in the HD & Lightnings are the only trannies that the ECU will communicate with...though I could be mistaken on this.
I read a post from another guy on another forum who did the mod. He said it took him a LOT longer than he anticipated, and he said he would not do it over again if he knew then what he now knows.
Unfortunately, I can't recall where I saw the post. But I'm unaware of any type of kit that would make this job easier.
At any rate, I ended up puttng a Porcharger onto my truck.
I have the new ECU. I guess mating the wires is the chore. For that, I could do with the pin-outs. I spoke with a guy "Steve" at Ford Racing, and he offered to fax the pin-out to both ECU's....but nothing ever came.
My 4.6 now has PI heads, cams, injectors, S-Trim Vortech, elec-fans, underdrive, true dual, modifies intake (to match PI) charge cooler, blah....blah...blah....As this is a disease, I want M O R E!!
FRP said that the U code on my trans is a good thing. Not sure why. He did recommend a cooler beyond what is already there...but made no mention of anything else.
I've got a similar setup as you, only I've got a Procharger. Fuel system mods, etc. But I've still got the crappy non-PI heads, and I don't have the underdrive pullies...won't that cause you blower to spin slower?
How much psi are you running? I've got 10.5, and I was afraid that the swap to PI heads would increase my compression ratio a little too much. Do you have a custom tune, or are you running an FMU? Any pinging?
What rear gears do you have?
I've got 4.10s with street tires (285/60R18) and I think they are great for centrifugal blowers - the revs are up just a bit but not too much.
I think a tranny cooler is a must. I've got one with a fan on it that comes on at 180 degrees, in addition to the puny one that came with the truck.
I am looking into swap an 03 HD engine into my 91 F150. I have the entire package: engine, tranny, wiring harness, ecu, radiator, trans cooler, intercooler, blah blah blah. I was wondering what the major difficulties would be there besides new instruments.
pronstar.....yes and no about the pullies. I have an oversize on my alt, stock on the waterpump and micro on the crank. Vortech supplies a new, oversized pulley for the centrifugal. So....it makes NO difference in the blower. I also can't run crazy psi (well....I could now that I'm swapping) because I'm sittin on over 13:1 if I go over 5lbs......no good wothout o-rings and a hella machining bill.
Vortech also supplied a new FMU. I had the option to have them give me a tune to mu ECU, but with all the other mods.....it didn't make sense. 650 lighter and two days apart got me the custom dyno tune the setup deserved.
I do ping from time to time. Never set a code, but makes me lift the "go" foot every time.....
Gears are something I definitely need. My tires are 40's.....but I have an 8.8 rear and I'm 4x4......so it is one of those "drive it till it's broke" things. Hopefully, the new motor (THAT I AM STILL LOOKING FOR HELP WITH) will bring the rest of the drive train to an early demise.....
Wow, you sure put a lot of effort into those pullies!
How much power are you putting down?
I'm at 318 to the wheels, torque is 410 lb-ft.
If you do the swap, stick to the Lightning 90mm MAF. It flows plenty even for modded Lightnings, and I've seen too many folks have MAF transfer difficulties with the Pro-M units. I odn't know of anyone who runs a Granatelli MAF, but they're like $400 - way too much considering you won't get significantly more flow IMHO.
A higher-stall converter may make some sense but that L motor will be putting a lot of power down at low revs. If you retain your factory gears with those tires, it makes sense. If you tow, I wouldn't go much higher. I'm not too fond of high-stall converters for towing, as you get a bit more heat because it locks-up later.
You'll have to run the COPs with the L motor, I'm not aware of a way to get around this.
I think you'll need a cutsom tune with the plenum, but I'm not 100% certain. The other mods you note (single blade Accufab, Pacesetter headers (short) and elec fans) shouldn't require a custom tune.
C&L claims no to the custom tune....unless you already have an agressive tune.
No prob with COP....just want to know what is what for the conversion.
Bigazz tires and 356 (?) make it a dawg off the line.....but rips once it goin. I was thinking a higher stall would help me off the stop. I knoe th eroots type make more torque than the centrifugal, so I may be o.k....but would rather KNOW up front. If it were 2wd, no biggie....but wranglin with the transfer is a bear...
No idea what HP.....didn't ask when the guys made my tune. I highly doubt if it is over 3.....