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4.7HO swap to regular 4.7

20K views 10 replies 10 participants last post by  Mike76945 
#1 ·
My buddy has an 01 Grand Cherokee with the regular 4.7. Runs like a champ with no issues. The truck does have some pretty major front end cosmetic damage from an accident.

We found an 04 in good condition with the 4.7HO that has a locked up engine. We were thinking of putting the regular 4.7 in place of the HO.

Has anyone done this? Can anyone give some insight, pointers, possible problems with doing that switch?

I'm aware the HO has knock sensors that the regular doesn't. We would switch the ECM as well. Anything else someone can think of?

Thanks in advance!!!
 
#3 ·
When I was originally looking for a new engine, my Jeep has the regular 4.7 so I figured I'd put the HO engine in instead. Well when pricing different brands out Jasper said they would not give me any warranty if I bought the HO engine because that isn't what mine originally was. They said I could have problems with the computer. But I don't no if I believe that. And I didn't do a Jasper.
 
#4 ·
There are quite a few differences between the two that make the HO a better performing little more robust engine. But long as you use the correct non HO ECM you should be fine. It'll run in the HP ONE but it's a more aggressive tune.
 
#6 ·
pulling this from deep memory: at some point the number of teeth on the tonewheel changed on the 4.7L; I don't remember what year.

If the new one doesn't have the same number of tonewheel teeth, it won't even start.
 
#10 ·
Still running strong? My 02 4.7HO blew a head gasket and I didn't catch it in time. Having a heck of a time finding a good HO in Canada. Put 2 HOs in it over the last year and they aren't lasting. 4.7 Standards are a dime a dozen, thinking of just putting a standard in rather than a HO but everywhere I read said it can't be done. Was happy to read your post :) haha
 
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