LBZ or LLY into an LB7 truck?

[dieselrealtor]

I am running across plenty of LLYs & LBZs for less money then the LB7s. I wouldn't mind having the newer engine for several reasons.

Are there significant modifications to the harness or truck itself with the LLYs & LBZs?

If I bought an engine complete with the engine computer, would this be a relatively easy project?

[Mark Rinker]

I'll leave the details to the experts on here, but the simplest approach would seem similar to my '98 L65 into a '94 swap...use your existing ECM and wiring harness, but replace the longblock, exhaust manifolds and turbo with the LLY or LBZ.

You would probably want to disable the EGR provisions, as your ECM won't be aware of them.

[dieseldummy]

From what I can remember the LLY and LBZ both use different proccesor setups something like 32 bit compared to 16 bit? Every thing about the LBZ is redesigned, for the better IMO. About the best you could do would be to use the LLY/LBZ shortblock and reuse your LB7 heads.

[More Power]

The LB7 & LLY use a FICM (Fuel Injector Control Module) to actually fire the injectors (controlled by the ECM). The LBZ's don't use a FICM - the newest injectors are driven directly by the new ECM.

I don't know if the LLY injectors would fit the LBZ heads.

The LBZ modules and harnesses may fit and operate correctly in the earlier trucks, but I don't know for sure. It may require all new underhood and in-dash wiring harnesses, which wouldn't be impossible to swap.

The Neutral Safety Back-Up switch is used to electronically identify the gear selection. In the earleir trucks, the NSBU was mounted over the Allison shift selector shaft.

Jim

[WhiteTruck]

Not related to the original question, but just a comment. The NSBU has been relocated as Jim mentioned, but is now INSIDE the trans and is now called the Internal Mode Switch. (IMS):rolleyes: Sigh, yet another acronym.

[dieselrealtor]

The LB7 & LLY use a FICM (Fuel Injector Control Module) to actually fire the injectors (controlled by the ECM). The LBZ's don't use a FICM - the newest injectors are driven directly by the new ECM.


With the 02 truck harness & an LLY engine w/harness & engine mounted controllers, is it possible that this would be a plug & play?

[dieseldummy]

The other problems you may run into is how the LLY/LBZ computer interfaces with the allison TCM and if it looks for a BCM or not. The best bet is to find a LB7. Have you talked to Merchant Auto?

[More Power]

White Truck, Thanks for the info on the NSBU....

dieselrealtor, Not likely.... I know the ECM & its electrical connectors are way different between the LB7 & LLY.

Jim