6.0 conversion questions & Socal machine shop recommendation

[mattt]

I'm at the beginning of a 6.0 swap in my 04 Tahoe Z71. The factory 5.3 and trans have over 300k and still get me to work every day, but they are tired and the engine leaks like an old VW.

I've procured a core 6.0 LQ4 and a set of "243" heads to run on it. I want to have the shortblock and cylinder heads rebuilt. Is there anyone in Socal that has a recommendation for a machine shop to do this work? I've talked to one, but wanted to see what other shops are out there and come with a referral?


I'm considering doing a TBSS intake swap on this at the same time. Is it true that the NNBS Silverado/Tahoe/Suburban/Yukon 5.3 intake manifold is the same exact manifold as a true Trailblazer SS 6.0 intake? If so, that will make finding one much easier than locating an intake from a limited run vehicle Trailblazer SS.

I have a few questions for those of you that have done the 6.0 swap.
-Did you swap your Y pipe and muffler to the 6.0 Escalade/Denali Y pipe and muffler. Our 5.3 Y pipes y down to one single connection before the muffler. The 6.0 Y pipe is 2 pipes all the way into the muffler. The muffler itself appears to be a different one as well, perhaps more performance oriented from the factory?
-Is the mass air flow sensor, throttle body, and fuel pump the same between a 6.0 Denali/Escalade and the 5.3 LM7/L59?

That's all I can think of for now, but I'm sure as this build moves along other things will come up and I'll post updates as it goes along.

 

[swathdiver]

Is it true that the NNBS Silverado/Tahoe/Suburban/Yukon 5.3 intake manifold is the same exact manifold as a true Trailblazer SS 6.0 intake? If so, that will make finding one much easier than locating an intake from a limited run vehicle Trailblazer SS.

While I do not know if they are the same part number, I have learned that there is no performance advantage of running one over the other. For all intents and purposes they are the same.

 

[Mechanic421]

Was looking at them on rock Auto like 133ish

 

[mattt]

Was looking at them on rock Auto like 133ish

???

 

[Mechanic421]

Trail blazer intake

 

[mattt]

Finally got around to posting an update here. Parts back from the machine shop and done. Block went to 020 and crank polished up.

Now to order pistons, parts and decide if it's going back together as an lq4 with dished pistons or an lq9 with flat tops. i have a pair of 317 heads and also a pair of 243 heads but will have to determine which heads to use once i decide on pistons so CR stays reasonable for a daily driver. Going to look at a TBSS for a song on Craigslist this weekend too. Slowly it's coming together.

 

[mattt]

Oh yeah, there are too many choices of camshaft. I'm tempted to just run the factory cam since I have it, but it sounds like a 6.0 benefits from a cam swap. Tahoe is my daily driver (run 87 mostly) and tow vehicle for the boat and dune buggy, so top end is not what I need. Any BTDT cam swaps with actual real world experiences? Thank you.

 

[mpope2]

Cam options are endless. I’ve been contemplating a BTR or TSP cam in my LQ9 swapped Sierra for years, but still running OE cam. If you go with Flat tops and 243s, the CR will definitely require tune and premium gas. I left the 317s on my LQ9 and is still running on the oe 5.3 parameters. I’ve held off on tune due to indecisiveness of going cam/converter route. As another member said, the part numbers between TBSS and NNBS intakes are different but should give you the same end result. The cam I’ve had my eye on is the BTR 30202111 torque cam. When I first did my swap I used the factory y pipe setup, but eventually switched to the Jegs off road catless y pipe. The only additional things I did during swap was to have the rear o2s tuned out for the off road y pipe, and egr parameter tuned out because I deleted it.

 

[iamdub]

If you can afford running 91-93 (both financially and just plain getting in the mindset), go with the high compression. More TQ across the board which will certainly help with towing. 11:1 CR is totally reasonable for a daily driver. Have the 243s checked and shaved cuz they're almost always a good bit over their advertised CC. More cruising TQ means more efficiency which means better MPG which lessens the actual cost of the high octane fuel. A thinner head gasket to get the quench to around .035" would raise the CR a hair but, more importantly, stave off detonation which opens up that tuning window. A small low lift cam is an option for more low-end if you wanna do that while it's apart.

 

[Rocket Man]

If you want to go boosted in the future you’ll want the LQ4 pistons and the lower CR but if you plan on staying NA then you probably want the LQ9’s. Cam can net you 30-40 hp over stock depending on what you go with. I’m running a VHP cam, Yella Terra roller rockers, Whipple, triple disc billet converter 2800 stall on my LQ4 and it’s strong.

 

[mattt]

Cam options are endless. I’ve been contemplating a BTR or TSP cam in my LQ9 swapped Sierra for years, but still running OE cam. If you go with Flat tops and 243s, the CR will definitely require tune and premium gas. I left the 317s on my LQ9 and is still running on the oe 5.3 parameters. I’ve held off on tune due to indecisiveness of going cam/converter route. As another member said, the part numbers between TBSS and NNBS intakes are different but should give you the same end result. The cam I’ve had my eye on is the BTR 30202111 torque cam. When I first did my swap I used the factory y pipe setup, but eventually switched to the Jegs off road catless y pipe. The only additional things I did during swap was to have the rear o2s tuned out for the off road y pipe, and egr parameter tuned out because I deleted it.

Thanks for the recommendation on the cam. I will check that out. Yeah, 243's with flat tops are definitely out as an option. I was thinking either lq4 bottom end with 243's or lq9 bottom end with 317's so the CR stays reasonable, around 10 -ish.

Since first posting this thread a few months back, I did a little research on GM Parts Direct about the TBSS vs NNBS intake. They are in fact the same part number according to GM Parts Direct.


The Y pipe difference is something that I've noticed when looking under Escalade's or Denali's that are parting out. I may pick up the factory 6.0 SUV Y pipe to swap into the Tahoe as well as the corresponding muffler which is also different. I have yet to look up part #'s for the fuel pump module to see if they are different from 6.0 SUV to 5.3/4.8 SUV.

 

[mattt]

If you can afford running 91-93 (both financially and just plain getting in the mindset), go with the high compression. More TQ across the board which will certainly help with towing. 11:1 CR is totally reasonable for a daily driver. Have the 243s checked and shaved cuz they're almost always a good bit over their advertised CC. More cruising TQ means more efficiency which means better MPG which lessens the actual cost of the high octane fuel. A thinner head gasket to get the quench to around .035" would raise the CR a hair but, more importantly, stave off detonation which opens up that tuning window. A small low lift cam is an option for more low-end if you wanna do that while it's apart.

Thank you. Definitely going to have the heads done prior to install. Multi angle valve job, bowl blend, surface & check for flatness. I will add having the machinist checking chamber CC to the list.

 

[mattt]

If you want to go boosted in the future you’ll want the LQ4 pistons and the lower CR but if you plan on staying NA then you probably want the LQ9’s. Cam can net you 30-40 hp over stock depending on what you go with. I’m running a VHP cam, Yella Terra roller rockers, Whipple, triple disc billet converter 2800 stall on my LQ4 and it’s strong.

Thank you. Definitely not going boosted, just building a healthy 6.0 and calling it a day. It will be better than the factory 5.3 that is worn out, and hopefully last 300k+ like my 5.3 did.

 

[Rocket Man]

Thanks for the recommendation on the cam. I will check that out. Yeah, 243's with flat tops are definitely out as an option. I was thinking either lq4 bottom end with 243's or lq9 bottom end with 317's so the CR stays reasonable, around 10 -ish.

Since first posting this thread a few months back, I did a little research on GM Parts Direct about the TBSS vs NNBS intake. They are in fact the same part number according to GM Parts Direct.


The Y pipe difference is something that I've noticed when looking under Escalade's or Denali's that are parting out. I may pick up the factory 6.0 SUV Y pipe to swap into the Tahoe as well as the corresponding muffler which is also different. I have yet to look up part #'s for the fuel pump module to see if they are different from 6.0 SUV to 5.3/4.8 SUV.

The Eskys and Denali’s don’t have an actual y pipe but instead they run dual pipes all the way to the muffler which is a dual in single out, and from the muffler back where it goes over the axle it’s a single pipe. It’s a much more open flowing system imo. If you look at ARH or Kooks you’ll notice they don’t sell a Y-pipe for this year 6.0.

 

[iamdub]

Thank you. Definitely not going boosted, just building a healthy 6.0 and calling it a day. It will be better than the factory 5.3 that is worn out, and hopefully last 300k+ like my 5.3 did.

Build it right (sounds like you're level-headed about it) and it should. I just finished a refresh on my 5.3 to commemorate it's 200,000-mile mark. Left the bottom end as-is except for the obligatory new oil pump, timing set, gaskets, etc. but added a small cam, shaved heads, thinner head gaskets, headers, mild torque converter and servos in the trans. Everything inside looked plenty fine and even surprising for the mileage. I'm right around 10.25 CR. I wanted 10.5-11, but left some extra wiggle room with the PTV clearance due to the aged bottom end possibly slinging the pistons higher than when fresh.

 

[mattt]

The Eskys and Denali’s don’t have an actual y pipe but instead they run dual pipes all the way to the muffler which is a dual in single out, and from the muffler back where it goes over the axle it’s a single pipe. It’s a much more open flowing system imo. If you look at ARH or Kooks you’ll notice they don’t sell a Y-pipe for this year 6.0.
View attachment 250039

Thanks for the picture. You are right, I guess it's not a Y pipe but instead 2 individual pipes that go into the muffler.

Anyone already BTDT and found that these will bolt into a 5.3/4.8 Tahoe? Are the mounts the same or is there re-engineering involved in swapping to the factory 6.0 dual pipes?

My thinking is if it's what the factory did, it was done for a reason as they could've saved a few pennies per vehicle if they had one standard Y pipe setup for all SUV's.

 

[adventurenali92]

The Eskys and Denali’s don’t have an actual y pipe but instead they run dual pipes all the way to the muffler which is a dual in single out, and from the muffler back where it goes over the axle it’s a single pipe. It’s a much more open flowing system imo. If you look at ARH or Kooks you’ll notice they don’t sell a Y-pipe for this year 6.0.
View attachment 250039

I’ve never seen the Escalade LQ9 setup, but on my 2006 LQ4, it has a the dual pipes coming down into the muffler, but my stock was a dual in/dual out muffler and then after the muffler the two pipes flow back into one before the axle to the single out exhaust. Not a dual in/single out like you said. Maybe a specific change to the 2006 model year? Maybe the earlier year 6.0 SUVs had the setup you’re talking about?

 

[Rocket Man]

Thanks for the picture. You are right, I guess it's not a Y pipe but instead 2 individual pipes that go into the muffler. Anyone already BTDT and found that these will bolt into a 5.3/4.8 Tahoe? Are the mounts the same or is there re-engineering involved in swapping to the factory 6.0 dual pipes?

My thinking is if it's what the factory did, it was done for a reason as they could've saved a few pennies per vehicle if they had one standard Y pipe setup for all SUV's.

I believe the only mount before the muffler is the one that bolts to the side of the trans so if you don’t have one of those you could grab one off a Denali/Esky. I believe they did the exhaust different for performance with the 6.0.

 

[mattt]

I believe the only mount before the muffler is the one that bolts to the side of the trans so if you don’t have one of those you could grab one off a Denali/Esky. I believe they did the exhaust different for performance with the 6.0.

Are those the ones that are showing in the picture you posted that look like an L shape round rod after the cats?

 

[Rocket Man]

Are those the ones that are showing in the picture you posted that look like an L shape round rod after the cats?

Yes. I looked up the parts on a dealer parts site and the Tahoes use the same mount although I don’t see those same rods on those y-pipes so you might have to get one from a wrecking yard Denali/ Esky if you don’t have that bolted to the side of your transmission.