Engine swap '04 Tahoe 5.3 to 6.0

tRidiot

Full Access Member
Joined
Dec 21, 2011
Posts
359
Reaction score
272
I believe it's all one piece... seems I saw a replacement new harness available recently for a coupla hundred somewhere.

This may have been what I found - I probably would have considered it when doing my motor swap, had I known it was easily replaceable.

 
OP
OP
M

mattt

Full Access Member
Joined
Mar 27, 2014
Posts
682
Reaction score
241
Steam line poll: What is the consensus on which steam line is better to use, the 4 port from earlier 99-00 vehicles, or the block off plugs in the back of the cylinder heads and the standard '04 front steam line that vents the heads up front?

I have both available. Anyone venture a guess why GM didn't continue the 4 port steam line like the earlier vehicles had?
 

iamdub

Full Access Member
Joined
Apr 23, 2016
Posts
16,482
Reaction score
30,807
Location
Li'l Weezyana
Going thru things today since my buddy wasn't able to help drop the long block in the Tahoe today. I was looking at part of the engine wiring harness and a question came up. Is the engine harness all one piece, including the lower portion that wraps around the oil pan up front and grabs the starter, oil pan sensor, A/C compressor? Or is that lower part sub-harness separable and connected to the main harness somewhere with a connector? Asking because if it were replaceable, I'd be considering replacement on that lower part.

I've dealt previously with Mustang 5.0 EFI harnesses, and there are 3 separate harnesses that inter-connect with Q/D plugs making up the complete engine harness.

Is the '04 Tahoe engine harness all one piece or are there possibly connection points that I missed? Thanks.

One piece.


Steam line poll: What is the consensus on which steam line is better to use, the 4 port from earlier 99-00 vehicles, or the block off plugs in the back of the cylinder heads and the standard '04 front steam line that vents the heads up front?

I have both available. Anyone venture a guess why GM didn't continue the 4 port steam line like the earlier vehicles had?

I'm with @Mudsport96. I've read that it was a harmless penny-pinching move. The 4-port is better, but not necessary. If it were me, I'd use the 4-port if it were available. Especially on a performance-oriented build. I'm keeping a look out for one and have spare gaskets on hand for that magical day when I find it.
 
OP
OP
M

mattt

Full Access Member
Joined
Mar 27, 2014
Posts
682
Reaction score
241
Thanks for all the replies above guys.

For future reference on engine removal, I meant to post up in the first post that you can in fact remove a long block engine(block, heads, balancer, flexplate) without dropping the front axle, or removing, disassembling the front core support. All other ancillary parts were removed with the engine in place, intake, exhaust, accessories, water pump, etc. It was extremely tight coming out, distance wise between the core support and the back lip of the engine compartment(above the firewall setback)....like an inch or less. But it will come out.

I removed it with a forklift and lifting straps which probably helps too, since the forklift can lift straight up and down and tilt when necessary. That in contrast to an engine hoist which lifts in an arc motion. If you remove the balancer, it will come out with a ton of extra clearance.
 
OP
OP
M

mattt

Full Access Member
Joined
Mar 27, 2014
Posts
682
Reaction score
241
Been having a harder time lately finding time to dedicate to the reassembly, but finally had a free afternoon to get after it. Working on the reassembly today and have a few tech questions, from deep in the weeds.

I've seen two different style exhaust manifold bolts, 1 with a smaller head and 1 with a larger head. I'm guessing they were updated by GM to try to stop them breaking off in the cyl heads. Which exh. manifold bolt is the better, or newer of the two? Just about ready to reinstall the exh manifolds. Is there any factory manifold that is a better choice, perfomance wise, than the standard truck manifold off the original 5.3? I'm not sold on changing to headers at this point, from a cost standpoint and the fact that they heat up the engine compartment.

I've seen replacement studs & hardware available for the outlet side of the exh manifolds. Is replacing those a "gotta do it" thing or will the original rusty ones live on for another 300k? The nuts took forever coming off, but no thread galling or breakage.

The original crank position sensor and cam position sensor were functional when I tore everything down. I looked at replacing both with GM parts but GM is pretty proud of those things now. Last time I had looked they were ~$50 for both IIRC. So I guess I'll be re-using my originals. However, I'd like to replace the O-rings to ward off any oil leaks from these 2. Anyone have a part # or O-ring part # for these two? I found a seller on Ebay offering a replacement for $20 but figured I'd see if there is a common O-ring I can source locally?

Thanks all!
 
OP
OP
M

mattt

Full Access Member
Joined
Mar 27, 2014
Posts
682
Reaction score
241
Let's see some pics or description of gussy'd up engine compartments. I regret not painting the block now, but what's done is done. However, I've been considering spraying some paint color on the accessory bracket after seeing how much better a fresh coat of black paint on the balancer looks.....nevertheless, seeing the balancer once installed is fleeting. If you spent some time with paint or other details in the engine compartment, let's see. I'm all eyes on suggestions. Thanks again.
 
Last edited:

Tonyrodz

Resident Resident
Joined
Feb 16, 2012
Posts
28,474
Reaction score
38,287
Location
Central Jersey
Been having a harder time lately finding time to dedicate to the reassembly, but finally had a free afternoon to get after it. Working on the reassembly today and have a few tech questions, from deep in the weeds.

I've seen two different style exhaust manifold bolts, 1 with a smaller head and 1 with a larger head. I'm guessing they were updated by GM to try to stop them breaking off in the cyl heads. Which exh. manifold bolt is the better, or newer of the two? Just about ready to reinstall the exh manifolds. Is there any factory manifold that is a better choice, perfomance wise, than the standard truck manifold off the original 5.3? I'm not sold on changing to headers at this point, from a cost standpoint and the fact that they heat up the engine compartment.

I've seen replacement studs & hardware available for the outlet side of the exh manifolds. Is replacing those a "gotta do it" thing or will the original rusty ones live on for another 300k? The nuts took forever coming off, but no thread galling or breakage.

The original crank position sensor and cam position sensor were functional when I tore everything down. I looked at replacing both with GM parts but GM is pretty proud of those things now. Last time I had looked they were ~$50 for both IIRC. So I guess I'll be re-using my originals. However, I'd like to replace the O-rings to ward off any oil leaks from these 2. Anyone have a part # or O-ring part # for these two? I found a seller on Ebay offering a replacement for $20 but figured I'd see if there is a common O-ring I can source locally?

Thanks all!
I'd go with aftermarket exhaust manifold bolts, possibly ARP. I bought some stainless #8 bolts iirc from Michigan Motorsports.
If you're not sure about the O rings, if you have a Harbor Freight locally they sell a whole O ring kit with a bunch of different sizes for a really reasonable price.
 

Forum statistics

Threads
118,799
Posts
1,634,459
Members
79,791
Latest member
Blu88
Top