Caddy 6.0 Install

[jough]

I have a 2004 Z71 with a bad 5.3 (uses lots of oil and loses lots of coolant).
Anyway, it is in the shop to get a 2005 Cadillac 6.0 (LQ9) & 4L65E installed. My questions are: 1. The shop wants to re-use the existing 5.3 Flex-Fuel engine computer instead of the Caddy 6.0 computer. Is that ok? 2. The 2005 Caddy has the returnless fuel line. My 2004 has a return line. I am thinking to use the driver side fuel rail from the 5.3 on the 6.0 intake manifold. What else should I do? Naturally I want power and decent fuel mileage.

 

[hoe]

I have a 2004 Z71 with a bad 5.3 (uses lots of oil and loses lots of coolant).
Anyway, it is in the shop to get a 2005 Cadillac 6.0 (LQ9) & 4L65E installed. My questions are: 1. The shop wants to re-use the existing 5.3 Flex-Fuel engine computer instead of the Caddy 6.0 computer. Is that ok? 2. The 2005 Caddy has the returnless fuel line. My 2004 has a return line. I am thinking to use the driver side fuel rail from the 5.3 on the 6.0 intake manifold. What else should I do? Naturally I want power and decent fuel mileage.

Nice, I have had my lq9 in my 01 for about 7 years now. Runs like day 1! I would reuse the existing ignition and throttle body! Thats what I did cause I had Drive by cable. Your 04 will be drive by wire. The 6.0 injectors are bigger, to feed the size engine. You can keep the 5.3 injectors and get the computer tuned. You can also put the 6.0 injectors in your intake too. Just be aware it will runs like crap if you drive hard. You will need a computer tune asap, either way.

But well worth it!

 

[jough]

It turns out that both intakes have the same injectors, part number xxx628.
Installer had to convert the Caddy returnless fuel line to the one that was on my 5.3 flex Fuel.

 

[jough]

It is alive and back in my possession. Only about 30 miles on it so far.
It averaged 15.3 over mostly freeway, which is the same as my sick 5.3 was getting. Besides converting the 05 from returnless fuel line to a return set-up, the mechanic had to deal with the fuel pressure regulator.

 

[Tahoebigdog03]

Sweet what other mods did you do to it?

 

[jough]

Other mods? So far nothing. I am pretty sure that I want to get a tune, maybe injectors? I dunno. Maybe muffler?

Is there a finned aluminum transmission pan with drain plug that anyone would suggest?

 

[abishoff]

Other mods? So far nothing. I am pretty sure that I want to get a tune, maybe injectors? I dunno. Maybe muffler?

Is there a finned aluminum transmission pan with drain plug that anyone would suggest?

I run the Mag-Hytec pan, which add 2qts to the total. You should also add a tranny cooler if it doesn't have that already.