GMCtrk

iTrader: (27)

Wiring harness is THE SAME. All you need is a 6.0 longblock. EVERYTHING from my 4.8L swapped over.

Also, since you are looking at 05+ engines, I'd recommend an LQ4 rather than the LQ9. In 05 the LQ4 received LQ9 (LS2) connecting rods. So the only difference between the two is the pistons (flat for LQ9 and dished for LQ4). Also, you will save a lot. 05+ LQ9s command a huge premium. You'd save at least $500 with the LQ4. The LQ4 should run a little better on 87 too. Power difference is marginal. LQ4 was 335/370, LQ9 was 345/380. The only reason I went with the LQ9 was becuase with my budget I was looking at 05 down motors and the LQ9's had stronger internals back then.

69Boss302

Maybe it was the older 4.8's that needed a change? Or I misread something all together.

The reason I chose the 05+ was for the LS2 internals. But I didn't realize the hp/tq was bumped up to be so close to the lq9. I've already found a few lq9s right around the $1,000 to $1,400 range. I guess I will look at the lq4 afterall.

GMCtrk

iTrader: (27)

Where did you find a new LQ9 for $1000-$1400. If so, buy it tomorrow! I've never seen prices like that 05 and up.

Mine was a 2000 4.8. That's about as old as it gets sans 1999.

Also, I'd recommend getting your tranny beefied. I never go WOT for fear of my tranny going boom....145,xxx miles.

69Boss302

I'm going to call tomorrow but I won't have the money, I think, for another 2 weeks.


In regards to the wiring change, I may have been thinking about the 4.3 and not the 4.8

69Boss302

Today I made the deposit for the LQ9/pcm and should be picking it up next week. If all goes well, it will be in by the end of the month.


EDIT: question. I read earlier today that the Caddy PCM can detect the octane rating of the fuel being used. How does it do that?

69Boss302

I drove 800 miles roundtrip today and came home without the LQ9. The top end of the motor was covered in oil/dirt like it had been leaking since day one really badly. The left hand valve cover was cracked, mounting holes for the valve cover seemed bent(the bolts were anyway), metal on top of the head, holes in the intake and so on.

I couldn't see paying money for a 9,000 mile motor only to have to tear it apart to make sure there wasn't internal damage.


EDIT: Any issues with using the 07 LQ4's?

GMCtrk

iTrader: (27)

see, I told you. There's no way in hell you're getting a 9000 mile LQ9 for $1000. Good 05+ LQ9's go for 2000 plus all day. Trust me when I say that using an 05+ LQ4 is outstanding. The single difference is the lower compression which is a 10HP difference. Not even noticeable. Plus, they are about $500 cheaper.

69Boss302

I went with that particular motor because it was, on paper anyway, the best overall. Low mileage, marginally more expensive than the next best LQ4 and relatively close for me to inspect before buying.

There is a 32,000 mile 2007 LQ4 motor on carpart. Might give that one a shot next.

GMCtrk

iTrader: (27)

I don't think there's such thing as an 07 LQ4. I believe all 07+6.0 engines have L92 heads which will make your swap much more complicated.

69Boss302

oh. I'll stick with the 05 and 06 motors for the LS2 internals.

I was just assuming they would be an LQ4 from the car-part search. The 2007 motors come up in the search for a VIN "U" motor.

Thanks for the help GMCTRK.