Lt1z383

I have built the **** out of my 4l60e and been holding up to the lsa blower on 14 lbs now that I put billet shafts in this and a sonnax smart tech drum but I have decided to tow my camaro with it I just need to swap the 6l80e into it as will have a lot of pluses over the 4 speed other then just stronger. So many threads and got most of it all pinned down. Trying to get some more in one place so maybe can get my final answers and will help others too.
This is a 5.3 with flex fuel and this didnt have a fpcm as the 2007 trucks did which didnt help my low fuel pressure from boost but Thought maybe this needs to be known for the wire harness swap.
As many said didnt need drive shafts as the trans is almost the same length and mounts the same to cross member.
I have a 32 spline transfer case input shaft on the way that makes the t case then work out-----. 41 bucks
I measured the torque converter bolt spacing and it is the same between both transmisisons.
I already got from rock auto the dip stick and tube for a 6l80e----- 20 bucks
I got a new gm transmission line from a 2009 tahoe with aux trans cooler and 6l80e ------52.00 bucks
The transmission I got was also from a 2007 truck. I did this as the tcm/os on these is specific to years as valve body differences and tcm differences will not swap in stock vehicles. I do this for a living build and sell transmissions so know the headaches in sending these out to customers and what happens if they get the wrong year. So to possibly make it easier on me I got what the tahoe would have had if it was available for my year. I Know the denail and the escalade had the 6.2 and 6 speed and as I wanted 4x4 high and low so I didnt opt for either when I bought this new.
Anyway Knowing what I do about the tcm and programming I figured I was building my trans anyway so will be updating to the better late drum going with red clutches and some sonnax parts just to bullet proof this thing to my trucks power level.
The last thing I have to work out really is the way to wire this thing up. I have hptuners and I have a gm mdi2 with tiseweb access. So I can change my os in the ecm which is an e38 on this year but it doesnt have vvt just dod and flex fuel. So the big question is which harness should I buy for it? I see that true blue motor sport has a wire harness option but I have been having some weird shifting issues on this tahoe for years. Never sets a light but will bang lose the torque signal to the trans and set line pressure and sometimes goes into reduced power. I have swapped everything in this some things more then once like throttle bodies gas pedals ignition switches the tcm the ecm You name it I have changed it and problem still there on it. So I think its a wire harness issue so rathere swap the whole thing anyway.
So which one to get that will work with the 5.3 the elecrric fans the flex pump so on???? The only tahoe one is a 2009 but I know it has the vvt on those. I found some used a 6.0 but it was on a silverado not a tahoe that was part number 20821966 I found on another thread for a 2008 silverado 5.3 swap. I would assume the 2007 with a 6.2 wont be correct either as 6.2 has the vvt also. It might just be its pinned into another spot and I just dont use it. Im worried about the connectors on my existing pcm not working on the new harness and or other connections not working and having to cut up a lot of this to make it work. Maybe someone has an easy answer or I just buy this harness and try to make it work out. The question there is tahoe to truck changes.
Then what operating system into my ecm to make it work and what to flash to the tcm? So many other threads with out this info. I cannot use the 6.2 os so assume I will have to use the 2009 or 2010 tahoe os with a 5.3 and 6l80e to get my parameters at least close to make my changes back for the blower which is on a 2 bar os also so not sure if thats gonna be an issue when changing os. Sorry for the long post trying to get a lot of what I do know into one place for others and still touch I what I do need to figure out still. Thanks in advance for any help.