L5P in a REV truck?

[T9000]

Has anyone ported a L5P with a 6 or 10 speed Allison to a REV truck? What extra challenges are we talking about, aside from programming? Or is the LBZ / LML the sweet spot?

 

[Mogman]

I am not familiar with the L5P or the 10 speed. If the 10 speed is longer or bigger (dia) than the 6 speed I would say that would likely be an issue.
Other than that you may have to find some earlier components, one thing I had to use on the LMM was a LBZ oil fill tube as the LMM was too high.
Other than some minor things I would suspect the extra programming is but a mere drop in the bucket compared to shoe horning the 6.6L into a HMMWV
ONE thing is you do NOT want to start with a REV, its 3.08 gears are too high a ratio for the MP transfer case, there have been several installations that have grenaded at highway speeds, if you do plan on replacing the diffs with 2.56 units

 

[T9000]

I am not familiar with the L5P or the 10 speed. If the 10 speed is longer or bigger (dia) than the 6 speed I would say that would likely be an issue.
Other than that you may have to find some earlier components, one thing I had to use on the LMM was a LBZ oil fill tube as the LMM was too high.
Other than some minor things I would suspect the extra programming is but a mere drop in the bucket compared to shoe horning the 6.6L into a HMMWV
ONE thing is you do NOT want to start with a REV, its 3.08 gears are too high a ratio for the MP transfer case, there have been several installations that have grenaded at highway speeds, if you do plan on replacing the diffs with 2.56 units

I was thinking to use the 2.73 diffs, are both 2.56 & 2.73, 10k rated? Is only the 3.08 rated at 12.1k? Was thinking which one would handle better the 910 ft/lb the L5P delivers?

 

[Mogman]

I was thinking to use the 2.73 diffs, are both 2.56 & 2.73, 10k rated? Is only the 3.08 rated at 12.1k? Was thinking which one would handle better the 910 ft/lb the L5P delivers?

I cannot see why any one would be rated higher than the other, everything is the same but for the ratio, they used higher ratio diffs on the higher rated trucks because of the piss poor power of the Detroit. (and the piss poor 1st gear ratio of the 4L80)
I have used tunes up to 475 HP and have not been able to break the 10K shafts or 2.56 gears, I can however sling all the rubber off of the half shafts
2.73 gears would probably be fine and easier to find
Now your REV might have different output flanges because of the upgraded brakes, should be easy enough to swap them out.
IIRC all the 2.73 trucks were 12K also.
The AMC20s are pretty dang tough.

 

[T9000]

I cannot see why any one would be rated higher than the other, everything is the same but for the ratio, they used higher ratio diffs on the higher rated trucks because of the piss poor power of the Detroit. (and the piss poor 1st gear ratio of the 4L80)
I have used tunes up to 475 HP and have not been able to break the 10K shafts or 2.56 gears, I can however sling all the rubber off of the half shafts
2.73 gears would probably be fine and easier to find
Now your REV might have different output flanges because of the upgraded brakes, should be easy enough to swap them out.
IIRC all the 2.73 trucks were 12K also.
The AMC20s are pretty dang tough.

That’s great info as always, thank you!

 

[T9000]

How about the transfer case, can I keep the existing one (242 I think)? Or do I need to change that too to from the donor Duramax truck?

 

[Mogman]

The 242 will not bolt up to the Allison and not likely that it would live long, besides the shift on the fly TC is really handy, it does mean more work and a third control module.

 

[Mogman]

Looking at the pictures of the LP5 it looks to have a much larger turbo, I had to reduce the height of the LMM to about the same overall height of the AC compressor, you are going to have your work cut out for you. It certainly does not look like anything near the 2" body lift I used is going to work.

 

[T9000]

Looking at the pictures of the LP5 it looks to have a much larger turbo, I had to reduce the height of the LMM to about the same overall height of the AC compressor, you are going to have your work cut out for you. It certainly does not look like anything near the 2" body lift I used is going to work.

I see what you are saying, the LLY (from H1), LMM and LBZ are much closer together, while the L5P is over 7" taller, at least on paper. Even 4-5" additional would be tough to clear. but I hear it has been done. Will keep investigating, but at the moment the LBZ looks to be the sweet spot (basically LMM without DPF).

Thank you!

 

[Mogman]

I basically reduced the LMM to a LBZ, used a LBZ intake horn, oil fill pipe and the "other" stuff was simply removed.

 

[Mogman]

I believe the Alpha used the 4L80E and the 242 but they had it tuned to under 300HP

 

[Mogman]

The problem with the LBZ is most donor truck have a 5 speed Allison

 

[T9000]

I basically reduced the LMM to a LBZ, used a LBZ intake horn, oil fill pipe and the "other" stuff was simply removed.

I know what you mean by the "other" stuff On that line of thought, wouldn't the LML fall in the same size category and be just as good if not better as the LMM/ LBZ?

 

[T9000]

The problem with the LBZ is most donor truck have a 5 speed Allison

From online info it sounded like all 2006-2007 LBZs are 6 speed and I was just looking for the D vin code ( www.xtremediesel.com - The LBZ was the first Duramax to be coupled to the 6-speed Allison 1000 automatic, which proved capable of handling more power than the five-speed version that preceded it).

The reason for looking at newer engines is that they are available for about the same cost, but with lower mileage and newer.
I will see if there is a way to differentiate between 5 and 6 speed, that's great info, thanks!

 

[Mogman]

I know what you mean by the "other" stuff On that line of thought, wouldn't the LML fall in the same size category and be just as good if not better as the LMM/ LBZ?

The big problem with the LML is the crap CP4 pump, but that can of course be changed.
Yes the 2006 up LBZ had the 6 speed.
I am keeping my eyes open for a 2006-2011 donor truck at this time.
The only major issues with these are the way they dump raw fuel to clean the filter, the later LML and above have an injector in the exhaust.
Of course this too can be "dealt" with.

 

[Mogman]

You can actually convert a 5 speed to a 6 speed simply by changing the valve body and TCM (about $2500) other than that the rotating mass is the same.

 

[T9000]

The big problem with the LML is the crap CP4 pump, but that can of course be changed.
Yes the 2006 up LBZ had the 6 speed.
I am keeping my eyes open for a 2006-2011 donor truck at this time.
The only major issues with these are the way they dump raw fuel to clean the filter, the later LML and above have an injector in the exhaust.
Of course this too can be "dealt" with.

Oh yes, I forgot about the CP4 (went over all the differences a while back), you are exactly right, that's why I thought the LBZ (with 6 speed) and LMM are in the sweet spot. Things are starting crystalize in my head lol