gsjimmy

Ok, just got back home from CO. Dropped a trans on the way out (long story) and had to get a new rebuild done in Denver (read as Jimmy did zero 4 wheeling in Colorado). So now #5 cylinder is acting up again on the 3.7 Atlas engine and I'm tired of chasing my tail on this. P.O. rebuilt the short block and reinstalled a 140K mi head onto a new short block. Truck now has 180K on it, new 4L60 E trans (270mm input shaft - think S10).

So here is the plan: Install a used LM7 5.3 GEN III out of a Silverado Z71. Swap the Atlas bell housing for a V8 bell (Have a LS1 Bell in the shop) and use the 4L60E I have now. This will of course limit me to 320HP & 300 FT LBS of torque. So this is going to be a stock LM7 5.3.

I will be using the '09-12 Canyon V8 exhaust manifolds, the 09-12 V8 oil pan for a Canyon/Colorado PN 12624621, Current Performance engine mounts (non-V8 to LS Swap units). Assuming that the engine I find is in good condition (donor truck) this should get me everything I need to do the swap (physically anyway). May have to spring for a new Y-pipe/cats to plumb out the exhaust. The Atlas fuel pump runs at 70PSI so the regulator should handle the 58 LBS to the engine.

Wiring: This is the what do I do now section. Need to know about the need for a swap harness, or if the stock Silverado harness will work. Also how about reprograming the stock '07 ECU to run the '02 LM7 (Atlas 5 Cyl to LS V8). I do not want to lose my gauges or diagnostic port.

I did watch the Truck Tech episodes on the Canyon 2wd drive swap, researched as many swaps as I can find, looked at 355Nation.net for anything they may have. Trying to get this "Done in a weekend" (yeah, right)

Let me know any advise that you may have. I have already swapped an S10 to 5.3/4L60E and know those challenges.

gsjimmy

Dumb question, if I go with a Stand Alone harness and 0411 ECU, will my gauges still be operational? I believe that the VSS plug on the trans is part of the harness and that the BCU feeds that signal to the dash for speedo out put. But the ECU on a Canyon/Colorado is different than a gen III ECU (blue/green). Not certain that I will have any input into the cab to run the Tach, water temp, gas gauge or speedo.

Thoughts?

G Atsma

Gas, oil pressure should be OK, as ECM does not see them. Put a separate sender in for temp.

gsjimmy

With a separate temp sender will I need to go with a sep. gauge? BTW - thanks with the help on the S10.

gsjimmy

Still looking for the wiring PIN out and harness build directions. Found a 2003 5.3 to use in the swap. Now I need to thin out the harness and add the correct plug to use the E67 computer. Who in the group is modding these ECU's to delete the downstream O2's and remove the passkey system? I will need to get that done soon. Parts ordering will be starting soon. Want to have it swapped by mid-September.

gsjimmy

Second question: Just had the 4L60e rebuilt (3.7 engine, so light duty 27mm guts). Can I simply swap out the bell house to the S-10 4.3 unit? Not sure on the overall height of the converter, but seems to be different than the LS1 version. This would mean a shorter bell house, using the V8 pattern.