Just wrapped up my swap and some key things I learned.
1. If your donor engine comes with an e78 ecm (which is found with l96 6.0's and 6l90e transmissions) do not use it. Even though it comes with it and everything. Trash it and get an e38 and repin it with a gen 5 camaro maf sensor or one similar. I used the e78 and there are more headaches associated with that ecm it's unreal. Especially if you decide to cam it like I did.
2. Treperformance fuel pumps are garbage. Ordered 2 of them. 1 didnt even work when I got it and the other went out after 6 months at the tuning shop which required for me to have to buy another one and pay them to install it. I'm now using a deustchwerks (I think that's how it's spelled) 300 fuel pump which flows more than any 340 fuel pump I've seen and pulls 15 amps or less!
3. If you're running a 2wd 6l90 and want to mate it up to a np208 transfer case you will need to pull out the output shaft from the transmission and get a 32 spline input shaft for the np208. (32 spline allows for alot more meat on the output shaft compared to the 27 spline (I think its 27)). Then send off the output shaft and input shaft to moser engineering and have the output shaft cut down and resplined. I dont remember the part number but there are adapters that mate the np208 to the 6l90e that are less than 100 bucks. They're factory pieces. I think they're similar to a turbo 400 adapter to a transfer case. Youll also need to plug the two holes found on the back of the transmission case. I used pipe fitting plugs (or something like that) and put them in it. Then just put the shafts in and you're done with a functional 6l90.
4. Dont cheap out on stuff. I mean take a deal when you can but dont do what I did and cheap out on a crappy fuel pump and have to pay for it later.
5. Instead of buying say a be cool radiator or one of those high dollar radiators. Find a local shop that builds them. I got a high quality aluminum double pass radiator with two 12 inch fans and shroud for 425 from the shop. A way better deal.
6. The mpg will go up more than likely. I went from a tbi 350 and 700r4 getting 12-13 mpg on the interstate. To a cammed 6.0 (about 520 horsepower at the crank) and 6l90 and got 17-18 mpg on the interstate. The truck has a 3" lift and 33x12.5 mud tires and is an 87 4x4. That number may sound hard to believe but it was hand calculated and I couldnt believe it myself until I seen it. I thought something was messed up with my gas gauge at first until I filled it back up.
7. If it's your first swap. You're going to learn an absolute ton! And its oh so worth it when it's done.
If anyone has any questions I'll do my best to help out!
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