As of now im a 12v guy but i really have the itch to build up a duramax but not enough cash for a newer truck so i figured i'd hop over here to get some feedback. Anybody here know anything/have done a LLY head swap onto a LB7? I have been looking around but there seems to be a disagreement on whether or not the LB7 FICM can be retained? Anyone feel like doing a write up cuz I think this is the solution to the dreaded LB7 injectors. It would be for the greater good but I also fear I might have to do this on dads truck in a year or two... But i guess Im really just looking for somebody to spew info at me

Thanks,
Dennis

 

i dont see that being a easy conversion at all, considering what all is different, by the time you get done with it your just going to have the whole top side being lly and just the short block bing lb7, so at that point it would probably be easier to just swap a complete lly into the truck along with the needed wiring. we got into a similar deal with a bad engine on a customers truck. it was an lly and he brought us an lbz engine to put in it. ended up taking it all the way down to the long block and putting all the lly parts on including injectors then had to swap on the lly timing case / water pump because thats all different, even had to swap the cam gear and the crank reluctor ring to get all the sensors to work, then even had to reprogram the ecm with efi live because the cp3 regulator on an lbz is different then the lly so that required a custom table to get it to idle correctly. the main things im thinking about is the wiring and the return plumbing on swapping the injectors, i see you having to get a whole harness to make that all work. i could be wrong but i think there is going to be alot more that is different then what you may be thinking, altho i havnt ever tried this swap so i dont know for sure.

 

I have seen the impossible! - Duramax Diesels Forum This is the thread i was looking at. Its long but very interesting. If you feel like reading it and making sense of some of this stuff then great if not then too bad, its your choice. Long story short these guys say it can be done for about the same price as doing 8 new lb7 injectors. Look for the guy named Hawk355, he says that he has done this conversion but there are also a few more on there who have too.

Dennis

 

after reading that whole thred it looks like its going to depend on what year your dad's truck is as to what all would have to be done, there were some good write ups in that thred

 

His is an 04 which seemed to be the easiest

 

yeah if i read all that right on an 04 looks like its just a plug and play as long as you have the lly ecm and ficm you can just unplug the body wiring and plug it right back into the lly engine wiring as long as you have everything, only thing i see is that you would be chaning so much that it would be alot easier to just drop in a "running" lly engine, but thats going to depend alot on the price of the parts.

the problems we ran into was with using the lly harness on the lbz engine, that turned into a nightmare along with all the broken parts from the wreck the lbz came out of

 

Well this would just be a project i would do in my shop at home so I would rather stay away from a complete engine swap

 

staying away from a complete engine swap because of the cost?

 

Yes but also I dont have an engine hoist nor have I ever swapped one before.

 

have you ever pulled the heads off of a duramax before?

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the book calls for 16 hrs to swap an engine out....or 33 hrs to do head gaskets