4.8 to 6.0 Swap

bixster_inc · February 22, 2012

I know this is a tired question but I want to do the 4.8 to 6.0 swap, I've been reading hundreds of posts and there are a few questions I have. My truck is a '03 GMC Sierra RCSB, 4.8, 4L60 tranny.

1. My current transmission will not handle the 6.0 for long, so I want to get a 4L80E or 4L65E but will they hook up to the stock drive line without modification?

2. Is there really that big of a difference in power between the LQ9 and LQ4? Either way I plan to move my headers, TB spacer and cool air intake system over to newer motor and install a more aggressive cam (I'll research that later) and get a tune that when combined with the other items will push me up over 400HP.

3. Has anyone done this in California? I talked to my smog guy today and he was telling me that as long as the engine I am installing is same year or newer I shouldn't have a problem getting it barred.

4. Any Ideas what my current engine/transmission in worth? 155k miles and always ran synthetic.

5. Last but not least, everyone has said that this is one of the simplest swaps but what are some hang ups anyone has encountered I need to be prepared for once I start?

Any advice would be appreciated, thank you.

Chris · February 22, 2012

a guy on here from santa clarita, ca did this. he did an lq4. he also has a built 4l60e and rearend. his name on here is DRT_RUNR

Silverado4x4 · February 22, 2012

Dont forget your going to need all the computers, wire harnesses etc for the newer bigger motor. Probably cheaper to just sell the truck and get a truck will the 6.0. Its not just a simple engine tranny swap.

Chris · February 22, 2012

all the same wiring. just need a long block and wiring. the intake is the same. a tuner like black bear can reprogram for you

oldschool327 · February 22, 2012

Long block, retune, and beef up the trans. Smog is good as long as the motor is from same or the newer as your smog guy stated

bixster_inc · February 22, 2012

How could I beef up the transmission? I'd hate to spend the money on upgrading the 4L60 if the 80 would be better.

tbhuge · February 22, 2012

http://gmfullsize.com/forum/showthread.php?t=150875

If you are thinking about forced induction (turbocharger or supercharger) go with the LQ4 because of the lower compression ratio.

oldschool327 · February 22, 2012

Any good shop can build you a 65e or 70e out of your 60e that will put an 80 to shame for less than you think.

Even a 60 with an hd2 kit would hold if done right.

nickvrebel · February 22, 2012

the swap is simple if you know how to pull and replace a motor, it's literally a remove and replace. all you need is the complete long block, you don't need accessories or the intake, but sometimes you'll get them in a used package.

*the smog guy won't be able to tell the difference unless you open your mouth about it - the motors are IDENTICAL once installed with the exception of a number stamped on the heads, they are not looking at that and wouldn't know it if they saw it.

*this is a direct swap

*I wouldn't pay the extra for a LQ9

*check out DRT_RUNR's thread in the performance section, I have lots of info there already

bixster_inc · February 23, 2012

I appreciate everyones input, I keep trying to find DRT_RUNR's thread but no luck, link?

oldschool327 · February 23, 2012

Search members and look for his topics

nickvrebel · February 23, 2012

here's the link:

http://www.gm-trucks...ap&fromsearch=1

just know that your will need a 2001.5+ motor. you are looking for a motor with aluminum heads, one with cast iron heads will NOT work (the cast iron heads suck, but the real problem is that the crank shaft will not worn on your setup)

Chris · February 24, 2012

the california smog law is that if youre swapping motors it has to be a motor that will pass your year's smog requirements, and has to be from a vehicle that is in the same GVWR class. DRT_RUNR has his pass no problem because from the outside they look the same. im doing a swap when mine craps out