ditched the 8.1 swap and decided to go with the 7.4 (engine swap 5.0 to 7.4).

[496BBC]

I've been toying with the idea of swapping my 5.0 for a 7.4 in a 96 K1500,

I was going back and forth on the 8.1 or the 7.4 but have now settled on the 7.4.

I'm running a 0411 computer and have been looking for a factory combo that used the 0411 with the 7.4 but have not came across one yet. I have read on the different forms that it has been done but just have not located the correct truck to pull the tune from.

The next issue will be the wiring harness, I picked up the harness and computer from the donor truck but it is from a 98 with the extra plug on the passenger firewall of which the 96 does not have. I can use the injector harness from the 98 harness but that is about it. I may just mod my harness since its already repined for the 0411, suggestions anyone?

I'll start tearing down the motor and checking things out soon as I get some time. I plan to install the ZZ502 cam and replace the injectors once tore down.

Anyone familiar with this swap that can offer any items that I need to address before I get deep into the install?

 

[88GMCtruck]

To my knowledge, there was no factory 454 truck with a 0411 computer. I have a 0411 swapped 454 and it has a custom tune.

I'm not sure of the differences in wiring on the 96 VS 98 454... What does the extra plug look like? The only two things i know of on the firewall passenger side in a 454 truck would be if it was a 1-ton with the borg warner transfercase, they had an external relay for the transfercase located there, or one of the firewall mount reel lights.

 

[someotherguy]

My memory is extremely vague on this but there were some medium duty trucks right at the tail end of GMT400 production, either very late 90's or early 2000's, that had the 7.4 with coil paks. Not to be confused with the 8.1, I do recall someone else posting about them and it was confirmed they were 7.4's. Going out on a limb here but they would have required a PCM with support for that ignition setup. The tune would probably be some crummy conservative tune, but at least you'd have a PCM to start with.

Richard

 

[88GMCtruck]

My memory is extremely vague on this but there were some medium duty trucks right at the tail end of GMT400 production, either very late 90's or early 2000's, that had the 7.4 with coil paks. Not to be confused with the 8.1, I do recall someone else posting about them and it was confirmed they were 7.4's. Going out on a limb here but they would have required a PCM with support for that ignition setup. The tune would probably be some crummy conservative tune, but at least you'd have a PCM to start with.

Richard

You are correct, the L21 used in medium duty trucks had a 0411 PCM but again, they were coil near plug. I would imagine you would need to modify the programming to get a standard distributor to work though.

If you are putting a cam in you will be tuning the truck anyway. Not sure if you were hoping to just swap a PCM in and run it, tune yourself or have it tuned.

 

[someotherguy]

Hell I was figuring it was a benefit. Convert! Get rid of that stupid plastic distributor and EZ-crossfire cap.

Richard

 

[88GMCtruck]

I've actually been thinking about converting mine actually, since I have the 0411 and all that. Only problem would be the mounting solution....

 

[496BBC]

I've located a fix for the 0411 computer tune for the 7.4 so that's behind me.

I'm going to get it running on the standard ignition and then move to the CNP setup latter.The parts for the CNP conversion can be gotten either from the L21 or eficonnection and I'll have to work out the programing when I go down that road.

The L21 was an option for suburbans and trucks around 99-00 per Wikipedia. The L21 used an odd looking computer, looks like a 0411 but with a rounded face at the plugs. I'll have to find someone smarter than me to tell me if that program will work in the 0411.

I'll have to work through the list and see if I can find a combination that will work.

The 98 harness has around 6 wires going through the passenger fire wall right at the heater core and the 96 doesn't have those wires entering on that side. Not a surprise as I had read about this differentce already. I'll probobly get a 96 2500 harness and mod it for the 0411.

Neal

 

[496BBC]

I had stumbled across a web page back when I started looking at this swap that had all the parts listed to convert the L29 to CNP like the L21 but cannot find it now, had everything needed listed.

Neal

 

[496BBC]

The valve covers from the L21 will work to mount the coils

I Havant looked but I can imagine the price

Neal

 

[skylark]

The valve covers from the L21 will work to mount the coils

I Havant looked but I can imagine the price

Neal

I would be remote mounting the coils.