I didn't know where to post this question, so here it is. I have a 05 Sierra with 5.3/4L60. I'd like to swap trans and maybe engine to 6.0/4L80 without too much modification to computer and harness. I believe the 80 harness is different. Would a 4L70, 75 use the same harness as the 60? This truck is in great shape but 225k miles and I'm original owner. I have to pull trans to fix leaks and planned on rebuilding 60. But if a 75 or 80 is easy I'd prefer to swap.
05 Sierra engine/trans swap
- Thread starter Cajun83HO
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I think your harness will work for both 5.3L and 6.0L and 4l60E and 4L80E. The ECM would need reprogramming methinks.
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Yes the 4L60/65/70E's use the same wiring connections.
I recommend going with the 80E transmission. There is a detailed write up on the swap in my GMT900 thread (linked in my signature). A GMT800 will be similar and the information is out there. It does require a segment swap on the tune to run the transmission. I'm guessing an 05 5.3 is Gen III architecture (knock sensors in the valley cover, cam sensor in the rear of the block, 24X crank trigger wheel, etc.)? Is it DBW or DBC? Somewhere around 04 or 05 was the crossover years, if I recall correctly.
As long as you go 24x-->24x or 58x-->58x, DBC-->DBC or DBW-->DBW its a direct swap from the 5.3 to the 6.0. But I would still flash your PCM with the tune for the 6.0 or a custom tune to get the most out of it. That is, unless if you are going to replace your PCM with the one for the 6.0. There are a lot of ways to overcome any mismatch. For example, in my brother's 78 Z28 we have a Gen IV 6.0 but are using a Gen III PCM because we wanted to run a DBC throttle body. That necessitated using the LIngenfelter converter box to translate the 58x crank signal of the Gen IV engine to the Gen III PCM which is looking for 24x. Also, extension harnesses are available for when you put a Gen IV motor in a Gen III car and need to extend the harness for the cam sensor up to the front cover (where it is on Gen IV motors). Another example is there are stand alone transmission controllers for the 80E.
The closer you come to finding a 6.0 that is equipped exactly like your 5.3 (engine generation, throttle body type, PCM generation) the easier and less expensive the swap will be.
When you find an engine you are serious about, ask some questions. There are lots of guys on here that are LS knowledgeable.
I recommend going with the 80E transmission. There is a detailed write up on the swap in my GMT900 thread (linked in my signature). A GMT800 will be similar and the information is out there. It does require a segment swap on the tune to run the transmission. I'm guessing an 05 5.3 is Gen III architecture (knock sensors in the valley cover, cam sensor in the rear of the block, 24X crank trigger wheel, etc.)? Is it DBW or DBC? Somewhere around 04 or 05 was the crossover years, if I recall correctly.
As long as you go 24x-->24x or 58x-->58x, DBC-->DBC or DBW-->DBW its a direct swap from the 5.3 to the 6.0. But I would still flash your PCM with the tune for the 6.0 or a custom tune to get the most out of it. That is, unless if you are going to replace your PCM with the one for the 6.0. There are a lot of ways to overcome any mismatch. For example, in my brother's 78 Z28 we have a Gen IV 6.0 but are using a Gen III PCM because we wanted to run a DBC throttle body. That necessitated using the LIngenfelter converter box to translate the 58x crank signal of the Gen IV engine to the Gen III PCM which is looking for 24x. Also, extension harnesses are available for when you put a Gen IV motor in a Gen III car and need to extend the harness for the cam sensor up to the front cover (where it is on Gen IV motors). Another example is there are stand alone transmission controllers for the 80E.
The closer you come to finding a 6.0 that is equipped exactly like your 5.3 (engine generation, throttle body type, PCM generation) the easier and less expensive the swap will be.
When you find an engine you are serious about, ask some questions. There are lots of guys on here that are LS knowledgeable.
All 4L80's are 5 times the value of a 4L60. A stock rebuilt 4L80 will withstand double what a built 4L60 can take.
I can't offer any information about stock ECU's for different transmissions, but I'd strongly urge you to do whatever you have to do to run the 4L80.
2007 Gen IV will be 58x. Look for a LQ4/LQ9 with an 80E out of a 3/4 ton truck, a van or a Suburban or Escalade. See if you can get the harness and ECM with it. It will make for an easy swap. Maybe even buy the donor vehicle if you have somewhere to put it.
I don't know about the "newer" engines, but the 6L in my 02 2500HD did not like the Gibson split dual exhaust. It seemed to pick up a bunch of lost torque (judging from uphill downshifts) with the single 4" Magnaflow. Just an FYI...
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