4l60e to 4l80e swap page
I recently did a 4l80e swap into my 2003 rcsb 4wd Chevy. Alot of people ask questions about it and I am finialy geting around to making a page describing some of what it took to get it in there. First though let me tell you about the reason for the swap.

My last truck was a 5100lb monster with great traction and quite abit of power. The stock 4l60e didn't last long so I upgraded to a fully built unit. i was running a 6.0L motor with a whipple blower at 9psi and as much as a 100shot of nitrous right out of the hole. My best ET was 11.92 on 8psi and a 75shot, 1.67 60', so turned all the way up i was probably in the 11.7 range. The first built tranny lasted only a few weeks but the truck had some serious wheel hop and bucking action going on. The tranny shop quickly sent me out a replacement and i took it easy on it till I got the wheel hop under control. It lasted alot longer but about the 2nd time i tried the 9psi and 100shot it let go too. The 4l60e's are geting stronger all the time and have a really steep 1st gear that is great for drag racing but for an all out project they still dont cut it.
click here for video of launch
click here for video of break
Now for the new truck, I got prety frustrated blowing up tranny in the last truck and a built 4l60e is prety expensive so i decided to go right for the 4l80e. A fully built 4l60e is rated at around the 600rwhp mark. From my times I was probably right around that mark and sure enuff it let go. I have no proof of this but have been told a STOCK 4l80e with just a shift kit is good to around the same horse power level and once built can take as much as 1200rwhp. I will be finding the limits of this one stock and once it lets go get it built.

First lets look at a parts list, this is for a 4wd and will vary some for a 2wd I am sure.

4l80e, flex plate from a 99+6.0 equiped truck, crank spacer kit, dip stick tube with dipstick, torque converter, torque converter cover, Speartech wireing harness, shorter tcase adapter, tcase from a 2500 truck, 2500 tranny lines.

For a 2wd you would drop the tcase and tcase adapter of course. You might need a larger yolk or the entire driveshaft from the 2500 but maybe not, on the 4wd all the yolks were the same.
I didn't really know what problems i might run into so I just started working on it and figured it out along the way. First step was to pull out the stock stuff, no problems there, then just start bolting in the new stuff but first you should try and get the new tranny lines installed, I was doing a motor swap at the same time so it was easy. I'm not sure what problems you might tun into doing with the motor in place. I am not 100%sure if you need a 6.0 flex plate but I had one siting here so i used it. You will need the crank spacer for anything except a 99-00 6.0 motor. The transmission just lifted right up and in, no tunnel problems at all. I put on the shorter Tcase adapter that came with the 4l80e and then the tcase. Right now it is all just bolted together and held up there with the tranny jack.

Better mention the torque converter here, some people mess this up. First, fill it up with oil, keep fillling it up till it wont fill no more, it is best to do this over a couple hour period. You have to put the torque converter on the tranny before you bolt the tranny up. It has several engaugement points so you have to push and turn, push and turn, I like to spin it around 2-3 full times while pushing on it. Once you have the transmision bolted to the motor you should be able to freely spin the converter, if it is presed against the flex plate and wont turn then it isn't engauged into the tranny all the way.

Lets talk about tcase for just a second here. My truck came equiped with a autotrack tcase, it wouldn't bolt to the 4l80e becasue the 80 has a larger output shaft. I used a manual HD case that i had laying around but the better set up might be to get an actual autotrack from a 2500truck, then it would probably plug right in and work. One thing to note it that the manual HD case is rated at twice the torque as the autotrack is but I have never heard of anyone breaking an autotrack. i ran into some engaugement issues with the manual case but i will get into that later.
Now that you have everything stuck up in there it is time to see what problems there will be. The tcase and adapter are siting back farther so the mount and shafts wont work. There are very few electrical conections on the manual case and alot that came off of the autotrack. The drive shafts are simple on the 4wd, the yolk sizes were the same for both transfer cases so all I had to do was change the length. I just took both shafts to a local drive line shop and had one made longer and one shorter. You will need to get a measurement, seem like it was about 1.75" but I didn't write it down and dont remember for sure. It cost me $150 tI change both shafts including all new Ujoints. The 2wd will be similar i am sure, just put it together and see how far off it is.

Next was the tranny mount, it tured out to be exactly 3" farthur back. At this point it might be worth looking at a LD2500 and see what it looks like under their truck, you might just be able to use a cross member from one of those. I decided to just add a pad on the back of the existing one.
The Speartech harness is prety simple to use, the short adapter is just that, it adapts the the plug that went into the 60 so that it plugs into the 80. There is also an extra speed sensor on the 80 that needs to plug into the pcm. That is what the longer wire is that is in the picture above. You might want to zip tie these wires to the existing harnes while the tranny is out. I just followed the harnes right up to the motor, over the intake, then just followed the large loom off to the right right to the pcm. The wires all ready have terminations attached and they are labeled. I used a saftey pin to puncture the rubber plug and then just slide the termination into the hole. You can see thru the plastic to make sure the termination is fully seated. The pcm will need a reflash to run the 4l80e properly, I didn't have LS1edit for my truck yet so i just sent it off to Speartech, they reprogrmed it and got it back to me fast. They are very helpfull and cheap. If you have LS1edit you can just send a flash file to them and they will send the edited one back for you to load.

link to Speartech
The dipstick tube from the 4l80 probably needs to be instaled along with the tranny, not sure if it will go in after everything else is installed. No problems with the starter or torque converter cover. The shifter cable hooked right on, the tranny i got had the cable bracket still atteched. Only problem here is i noticed a scratch on the front drive shaft a few days after the install, I think when in gear and under load it got close enuff to rub the spining shaft. to fix this i just bent the lever coming off the tranny shifter shaft. Next i attached the 2500 tranny lines, they fit fine under the truck on the tranny end but up near the radiator only one of them pluged right in, the other line was designed to go right to a cooler and I am not using one yet so it needed modified. It is easiest just to post a pic of what I did there. After geting it all hooked up I noticed it is real close to the grease zert on part of the steering, I used some tie wire to hold it up higher, it's not the best fix and I have to wonder if there are lines that fit better. The guy at the dealer wasn't helpfull at all, I didn't have any vin numbers for the parts i wanted and he acted shocked.

At this point I dumped in some oil and fired it up. After making sure it was full I took it for a spin. It worked great right off the bat. It has much firmer shifts than the 60 did. I eventualy put a shift kit in and now the shifts are GREAT. Fast and firm with no slip. I am only running about 400rwhp right now so it hasn't really been put to the test but it will be. I will add info to this page when i find out the limits of the tranny. Since the built 60 took me into the high 11's and this truck is lighter I am going to say if this one takes me to mid/low 11's then it is as strong as a fully built 60. A built 60 is over $2000, geting a stock 80 into your truck could be done for as little as 1/2 that depending on how much you paid for the used parts. The best part is if you do break it you should only have to do one rebuild and be set for ALOT of power.
The last part of the project is still not completely figured out. I was talking about transfer cases eairlier. I think the best bet would be to get the same style out of a 2500 that came in your 1500. If you had a manual shift case try and find that same style, if you had electric shift look for that and if you had an autotrack try and find one of those. Then you would probably not have any issues like i have right now.

My truck came with an autotrack but I have a manual shift case in there. I tried just leaving it all unpluged but with the case shifted to 4hi and nothing worked at all, the front diferential wouldn't enguage and the buttons did nothing on the dash. My cheezy fix was to tie the control modual from the autotrack up under the truck and plug it in, not actualy bolt it to the case though. Now i can use the buttons on the dash and it disengauges the front diferential and thinks it is shifting the case. It works well enuff but an autotrack case from a 2500 would be much better. I just leave the case in 4hi all the time, and when i hit 2wd it disengauges the front. When I hit AUTO it locks the front. There is one last thing, the manual case has only one speed sensor and the autotrack case had 2. leaving one unpluged gets me a "service 4wd" message as soon as i start moving. doesn't seem to be a problem though. Once again I think geting a autotrack case from a 2500 would fix this problem. If you want to see the pictures in more detail you can go HERE, just click on them till you find the one you want.