I have an 01 c1500 that was 4.8 auto, I bought a 01 LQ4 6.0 out of a C2500 auto. Dropped the motor in today and went to install my trans. and now my converter won't bolt to the 6.0 flywheel/flex plate. I know now I should have made sure the converter would bolt to the flywheel, but it had two bolt patterns, so I thought it would work. I don't see any weights on the 4.8 flywheel, and I haven't split the 6.0 from my 4L60E yet, but I don't remember any weights on the 6.0 flywheel either, but I do remember a spacer. Guess the 6.0 had 4L80 behind it, and the converters must have a differnt bolt patern. Can I just use the 4.8 fly wheel and bolts, or do I have to buy something special fly wheel to work with the 6.0 and 4L60?

 

I used the flywheel off my 5.3. I would think the same would apply to your case as well.

 

Thanks for the info, wasn't sure, didn't know if there might be a balance issue.

 

Isn't the crank longer in the 01 6.0's

 

No, he's good on the crank length. The '99 & '00 models had the long crank. He just needs to use the flex-plate from his 4.8L, and just make sure to remove the spacer from the rear of the crank. At 1st glance the spacer may look like it's part of the crankshaft, but it's not. You will notice a couple of extra bolt holes in the spacer besides the actual bolt holes to fasten the flex-plate to the crank, these are there for you to thread bolts into them to force the spacer off the end of the crank. Not always, but in some cases it will be stuck pretty well and may not want to come off otherwise.

 

Thanks for the replys. Thought I did all my home work on this, but guess not. I put an LS-6 cam and springs, 2200 stall converter and the rest of my bolt ons. Is there any other problems I'm going to run in too?

 

i have a 2000 gmc had a 4.8 automatic originally. I have swapped in a 6.0 from 2003 yukon got past most issues oil sending unit, DBC to DBW im still confused on the flexplate issue the truck runs and drives but i do feel a vibration seems tranny related im still using the factory 4l60e its been rebuilt but wondering about this vibration. Havent had it tuned yet but seems to run well shifts are a little firm do I need to get the ecm tuned to really get all the mmmmf out of it or does it make a difference also the flexplate should i have used te 4.8 plate ?????????????????

 

Start a new thread with more details. Ex Is the vibration only during a certain RPM range?