FJM

Hi everyone, I'm looking for some advice on a V8 swap for my 2009 4x4 Colorado. I currently have the 3.7 in there. I have read the many threads on this site about performing the swap and I hope that these questions are not redundant to those that may have been asked and answered previously.

I recently picked up a 2008 Chevy Express Van with an LY6 and a 4L80E dirt cheap. Truck was an absolute wreck. The engine has 260k on it but runs fine (I plan a full rebuild). The transmission had no reverse but otherwise shifted normally in forward gears. I drove it 100 miles to get it home without incident.

Since, it's a complete running vehicle I was thinking I could use almost everything in the swap. I'm an experienced hotrodder but I have not worked with Electronic setups before so I as your patience in advance. Here are the specific questions:

1. Can I use the Van's ECU in the Colorado without further programming?
2. Since the LY6 is a Gen IV engine, can I use a stock Colorado 5.3 wiring harness or do I still need to get one from Current Performance as so many of you have suggested in other threads? If I do need one from CP, could you please elaborate on the "why" ? I'm looking for full functionality of all accessories in this sway (Cruise, gauges, 4x4 etc.)
3. I would like to use the 4l80e if possible. The Van is a 2wd so I'm aware that I would need to get a different output shaft to match up to my 4x4 setup ( I've seen links on this site to the company that makes the adapter kit). Can I use the TCM from the van to plug into the stock Colorado 5.3 harness or the CP harness (I'm aware that the V8 Colorado from the factory used the 4l60e, similar to the one I have in the truck currently.
4. If the 4l80e is unworkable and I'm forced to stick with my current 4l60e, then the question of programming the current transmission comes next, particularly if I use the E67 ECU from the Express van as I mentioned above.

I think those are my big questions at the moment. This has been a great site for information. I hope that you can help with my questions. Thx.

_zebra

iTrader: (5)

you might honestly get a little better info on 355nation because they're specifically dedicated to the late-model mid-size GM trucks (versus mostly full-size guys here), and they LS-swap them all the time.

i will offer that as an H3 owner, i know enough to say so long as the van has an E67, you should be able to use either. the v8 colorado harness (also Gen IV) would likely be your most-direct swap option. you'll also want to make sure you grab some stiff front springs because even the stock v8 355s had aluminum blocks (~100lb lighter). also, they had a special oil pan & exhaust manifolds to fit around the front driveshaft in the narrow frame.

as for the 4L80: it's close enough in length that your driveshafts & crossmember should be fine (i think), but you'll need to swap in a 4x4 tailhousing (not just the output) plus a smaller input shaft (the 4L80 is 32spline). then you'll need to consider your diff ratios to account for the higher transmission 1st gear.

FJM

Thank you for your very thoughtful response. I am a member of Performance Trucks, Colorado Fans and 355 Nation forums. Good ideas come from everywhere.

I agree that it seems to make the most sense to use the stock 2009 Colorado 5.3 harness but as I said I'm not familiar enough with the nuances to appreciate things I might have overlooked. To be clear are you suggesting that I should try to swap the e67ecu and the TCM from the Express van directly into the Colorado? I really didn't consider the gear ratios that you mentioned. My Colorado is currently running 373's behind the 3.7. The 4l60e has a 3.06 first gear and the 4l80e has a 2.5 first gear. That's a significant gap but the 6.0 is 60% larger in size, so it might be a reasonable offset. At worst, I could go to a slightly looser Torque Converter to compensate.

I agree that I need a 4x4 tailhousing as well as the output shaft but I want to make sure that the electronics will work before I start working on the mechanical bits. As a second choice, I could go to a rebuilt 4l60e that's setup for a v8 but I've read so much negative info on the 4l60e. If I do go for the 60, then I have the question of which TCM to choose because of the gearing differences.

Any additional thoughts are very welcome. Thanks again.

_zebra

iTrader: (5)

i honestly ain't owned an automatic in almost 20yrs, so all my knowledge is from what i've read over the years...

but the colorado already uses an E67 and separate TCM (both v8 & i5), so as long as you flash appropriate tune info to them, it should still run fine. as for the 4L80 swap - i tune out when folks start discussing electronic differences. if you like your current final drive RPM, then a looser converter sounds like the better option - as long as you have adequate transmission fluid cooling.

FJM

Thanks a lot. My primary reason for thinking the 4l80 is that I've read so much negative news on the strength of the 4l60. And since I now have a 4l80 in hand, I'm wondering if I should go for it. The gearing on the 4l60 is better actually but with the bigger motor the 4l80 first gear difference should not be a real problem.

_zebra

iTrader: (5)

most 4L80 swaps are also in fullsize trucks, so your weight difference will help the gearing situation - should you go that route.

FJM

Good point. Thanks.

turboal1

I run the stock 4L60E trans in my 6.2 Colly, 500+ RWHP NO probs, just don't act
like an A-Hole. over 13yrs on tranny., 5yrs on the 6.2. plus i tow a 2 HD bike trailer.

FJM

Thanks for the feedback. Helpful. Maybe I just rebuild the 4l60 and add some of modifications that everyone is talking about.

turboal1

a Trans-Go shift kit and some good stronger after market parts will work well.for you.