jjacksonford

thinking of swapping out my 4.6L for a 5.4L

can i just swpp it straight across or is there pcm issues to resovle? i also had someone tell me that if o switch them i need to make sure they are both windsors or both romeos.. they have to be the same?

zap

The pcm's are engine specific. Probably cheaper and easier to go with a mechanical engine versus electronically controlled. Looked at swapping my 4.2 for a 5.0 since I had a friend with an extra pcm they wouldve given me when I blew my lower...decided it would be more efficient cost wise and fuel wise to swap over to a mechanically controled 3.9L Cummins diesel when I had the money.

deerski0156

Yeah whenever my truck decides to take a dump, im going to do a 3.9 4BT cummins swap and throw a zf5, 5 speed from an F250 in and do top-end motor stuff and a turbo and get about 450-600 horses with 710 ft-lbs. Theres a guy with a camaro on you tube who did that and its a fast little chevy.

Austin97

For your motor swap all 5.4s are Windsor motors so you have no problem there, it is what it is. Just make sure you get the whole motor, throttle body to oil pan. The best way to do a motor swap is to run the same PCM and get an SCT xcal 3 with custom tunes from Troyer or VMP. Changing PCMs is fine unless your truck does not have PATS and the new PCM does. Otherwise it is fine and all you have to do is reprogram the keys before it will start or you are deleting PATS anyway.

If you don't have a body lift a motor swap in these trucks is a pain in the ***. With one it's no walk in the park. I don't know enough about the cummins swaps to debate which is best, but 5.4 swaps aren't that bad, I would do one before messing with a diesel.

zap

I'm just gonna use my M5R2 until it goes. Then maybe look into a ZF5. The thing about the ZF5 is that its a dog-legged 4 speed with a granny gear where reverse should be. You never use first unless your loaded. I was thinking about maybe a Eaton 10 speed instead.

deerski0156

I had a buddy tell me to go with a tremec and Idk if it'll hook up.

zap

It's a racing transmission. The ZF5 is geared too low to really race with. But you would be able to compete in some pulls. I'm just after the Eaton because I really want a dog leg (best for racing by the way because you pull straight back from second to third, and fourth to fifth) but there are not many transmissions out there that will bolt right up to a Cummins block that are set that way. The Eaton is one of them. I really don't need the splitter on the rear end that gives the transmission it's high range. Wonder if they make a 5. Sounds like you will want a 4200 rpm gov spring (stock 4BT's are governed to 2800 rpm) but you'll need 60 lb exhaust valve springs. I was only going to go for a 3200 (anything over needs the exhaust valve springs) cause I'm after torque and mileage.

ColdOne

" Changing PCMs is fine unless your truck does not have PATS and the new PCM does. Otherwise it is fine and all you have to do is reprogram the keys before it will start or you are deleting PATS anyway."

Ok I swaped a 2001 5.4 into a 97 4.6. Just about thru with a project I should have not started. How do I disable the PATS on the 01 pcm?

I got the 01 motor, wiring harness and pcm, not the 01 body harness. HUGE PITA to sort thru every pin connection and get the COP's for 5-8 into the pcm harness (they are in a seperate plug not on the 97 body harness) 8 to 10 other wires to chnage location on also to correctly line up the 4.6 harness to the 5.4 pcm and motor harness.

Austin97

You don't. Like I said the only issue you can have is going from a non-PATS to PATS PCM. The best thing you can do is run the 97 PCM and get a custom tune for the 5.4.

zap

Another reason why I'd love to go mechanical...