05 Tahoe: 5.3 LM7 rebuild. simple upgrades?

[blueinkd]

05 Tahoe on +300K miles, 2WD, Daily driver/mobile office.

-Shortblock is headed to machine shop tomorrow for a bottom end rebuild. Using Scroggins Machine shop here in Houston.
-Looking to get another 300K miles from the refreshed engine. Cam bearing walked out during Cam removal, which lead to this rebuild.
-Getting a basic rebuild, which includes block inspection, honing, ALL bearings replaced, piston rings and some ARP hardware on the rods.
-Crank/rods getting inspected as well. You all get the picture.
-Machine shop doing the reassembly of shortblock and I will add the heads/cams/timing set when I get it back.
-I will be installing NEW lifters, oil pump, timing set, BTR Truck Norris Cam kit and new gaskets all around.
-New Rear main seal. Current ACD unit is less than 12 months old but might as well.
-The BTR Cam kit I got doesnt require a stall BUT I will be replacing the factory TC with another OEM torque converter.

-I do have a TBSS intake sitting in the garage, but that will have to wait until later. For now I just need the truck back on the road unless I can find all the missing components at a reasonable cost.

During the removal, I noticed the factory steam ports at the corners of the heads a bit ugly. Can anyone recommend a good replacement kit?
I see ICT has some nice options but way too much to sift through for what I need. Please point me in the direction of a simple replacement kit.
Any other things I should look at replacing on the engine while its out? Any complete ground strap kits I can buy that will include all grounding points?
I have already replaced the following items in the last 12 months:
-Coolant hoses and Tees.
-Water pump/thermostat
-ACD OEM power steering pump
-TSP shorty manifolds

Sorry for the long winded read, but wanted to get some suggestions from the fine folks on this forum.

 

[iamdub]

05 Tahoe on +300K miles, 2WD, Daily driver/mobile office.

-Shortblock is headed to machine shop tomorrow for a bottom end rebuild. Using Scroggins Machine shop here in Houston.
-Looking to get another 300K miles from the refreshed engine. Cam bearing walked out during Cam removal, which lead to this rebuild.
-Getting a basic rebuild, which includes block inspection, honing, ALL bearings replaced, piston rings and some ARP hardware on the rods.
-Crank/rods getting inspected as well. You all get the picture.
-Machine shop doing the reassembly of shortblock and I will add the heads/cams/timing set when I get it back.
-I will be installing NEW lifters, oil pump, timing set, BTR Truck Norris Cam kit and new gaskets all around.
-New Rear main seal. Current ACD unit is less than 12 months old but might as well.
-The BTR Cam kit I got doesnt require a stall BUT I will be replacing the factory TC with another OEM torque converter.

-I do have a TBSS intake sitting in the garage, but that will have to wait until later. For now I just need the truck back on the road unless I can find all the missing components at a reasonable cost.

During the removal, I noticed the factory steam ports at the corners of the heads a bit ugly. Can anyone recommend a good replacement kit?
I see ICT has some nice options but way too much to sift through for what I need. Please point me in the direction of a simple replacement kit.
Any other things I should look at replacing on the engine while its out? Any complete ground strap kits I can buy that will include all grounding points?
I have already replaced the following items in the last 12 months:
-Coolant hoses and Tees.
-Water pump/thermostat
-ACD OEM power steering pump
-TSP shorty manifolds

Sorry for the long winded read, but wanted to get some suggestions from the fine folks on this forum.

I'd still recommend a small torque converter. @pwtr02ss and I have the same CircleD converter. I believe it's the Trailblazer converter but with minor mods and upgraded components.

The steam ports are kinda hidden. The rear block-offs definietly are. If they bother you, why not just get new OEM ones? Or, clean yours and install new gaskets. I used neoprene (I think that's the material) O-rings from Napa. https://www.tahoeyukonforum.com/threads/growing-up-doesnt-have-to-suck.93510/post-1455933

How about a billet and O-ringed barbell from Sac City Corvette or Improved Racing?

I'm a firm purveyor of upgraded grounds and, more specifically, the Big 3 Upgrade. There are plenty of pre-fabbed kits but most seem to be halfway made up and you finish them after trimming the wires to length. Also, so many of them are CCA (copper-clad aluminum) which has a considerably lower ampacity compared the the same gauge in OFC (oxygen-free copper). OFC is pricey, but far superior. IMO, if you're gonna have to finish out the kit, you may as well just make it all from scratch. Determine what circuits you want, add up the length plus some extra and grab some OFC welding lead from your local welding supply house or search online for deals. I used 1/0 welding lead I had on hand and bought marine-grade lugs off Amazon with adhesive sealant-lined heat shrink tubing for mine.

Now would be a really convenient time to replace the engine mounts.

Either take your time and measure, adjust, measure, adjust, measure, etc. the front and rear covers and oil pan or invest in alignment tools. You can get tool sets for around $30 on Amazon.

Catch can?

Other than whatever that cam kit might not include that's needed, I can't think of anything else pressing.

 

[swathdiver]

5 angle valve job and refresh the heads and maybe a little bowl work.

 

[rockola1971]

With engine out, now would be a good time to replace the oil coiler lines. Whats the history on the tranny?

 

[iamdub]

5 angle valve job and refresh the heads and maybe a little bowl work.

Good catch. I read right past that, assuming he meant rebuilt heads. @blueinkd, if the heads have 300K and you want them to go another 300K, definitely have them rebuilt. A refreshing (especially the new guides and 5-angle valve job) plus a little upgrading as James outlined would complement the cam. I'd add a mild shave to get compression up to 10:1 and/or thinner head gaskets if you wanna get into it like that.

 

[blueinkd]

Good catch. I read right past that, assuming he meant rebuilt heads. @blueinkd, if the heads have 300K and you want them to go another 300K, definitely have them rebuilt. A refreshing (especially the new guides and 5-angle valve job plus a little upgrading as James outlined would complement the cam. I'd add a mild shave to get compression up to 10:1 and/or thinner head gaskets if you wanna get into it like that.

I already had the heads done at machine shop with a fresh valve job, new seals and the upgraded springs from the BTR cam kit. Thanks for the suggestions. Will make some notes once I go through them and report back.

 

[blueinkd]

Dropped off the shortblock at machine shop this morning.

 

[Mudsport96]

Well after they figure out what over bore it needs collaborate with them to find a piston that gives you at least 9.5:1 compression with the 706 heads. You want quench to be in the .044 range for best detonation suppression.
Don't know what you use it for primarily, just driving or much towing so other than that, i don't have much.

 

[iamdub]

Well after they figure out what over bore it needs collaborate with them to find a piston that gives you at least 9.5:1 compression with the 706 heads. You want quench to be in the .044 range for best detonation suppression.
Don't know what you use it for primarily, just driving or much towing so other than that, i don't have much.

I like it tight in an iron block- upper 30s (~.037", etc.) for quench.

The LM7 is factory advertised as having 9.5:1. I'd ensure it has at least this but would aim for 10:1 at minimum with that cam. Hopefully it won't need anything beyond a clean-up hone. But, if you gotta bore... My vote is punch it to a 346 and drop in LS1 pistons. But then, you really need 243/799s. 706s on an LS1 would be something like 11:1+ SCR. Fun, but likely not within the scope of blueinkd's project.

GM's combustion chambers are often much larger than advertised so the only way to know is to measure. While it's apart and being machined, there's no better time to measure and tweak to your liking. 706s have a nice small 61.5cc chamber, at least, that's what GM says. Confirm the actual size, factor in a thinner head gasket for quench and shave accordingly. Shaving is cheap power since the head refurbisher already has it on the mill if even just for a cleaning pass.

 

[blueinkd]

I like it tight in an iron block- upper 30s (~.037", etc.) for quench.

The LM7 is factory advertised as having 9.5:1. I'd ensure it has at least this but would aim for 10:1 at minimum with that cam. Hopefully it won't need anything beyond a clean-up hone. But, if you gotta bore... My vote is punch it to a 346 and drop in LS1 pistons. But then, you really need 243/799s. 706s on an LS1 would be something like 11:1+ SCR. Fun, but likely not within the scope of blueinkd's project.

GM's combustion chambers are often much larger than advertised so the only way to know is to measure. While it's apart and being machined, there's no better time to measure and tweak to your liking. 706s have a nice small 61.5cc chamber, at least, that's what GM says. Confirm the actual size, factor in a thinner head gasket for quench and shave accordingly. Shaving is cheap power since the head refurbisher already has it on the mill if even just for a cleaning pass.

Yeah it's literally just a daily driver, get me to work truck and back home. Only reason for the cam is cause why not. I love the chopy exhaust notes from cammed trucks. If I wanted to go fast I'd bought a camaro or a mustang. Too old for that stuff these days or my wallet not deep enough.

 

[blueinkd]

Figured I would used this thread. Got the block on the stand. Really pleased with the machine shop and their work. I used www.scrogginsmachine.com in Houston if anyone cares.

 

[mattbta]

What all did they do and how much, if’n ya don’t mind? When it’s time to pull mine, I’d drive from Dallas to Houston for good work. Plus, sister lives down there.

 

[iamdub]

Figured I would used this thread. Got the block on the stand. Really pleased with the machine shop and their work. I used www.scrogginsmachine.com in Houston if anyone cares.

What all did they do and how much, if’n ya don’t mind? When it’s time to pull mine, I’d drive from Dallas to Houston for good work. Plus, sister lives down there.

^^^What matt said. What they did, parts used, any issues found and corrected, and deviations from stock...?

 

[blueinkd]

Here is a picture of the invoice. Seems pretty thorough to me. They included all the old parts/bearings in a plastic bag. No expert here, but I have had machine work done in the past on SBF stuff by FordStrokers.com and this machine shop has a great local reputation.

 

[Tonyrodz]

Here is a picture of the invoice. Seems pretty thorough to me. They included all the old parts/bearings in a plastic bag. No expert here, but I have had machine work done in the past on SBF stuff by FordStrokers.com and this machine shop has a great local reputation.

Seems very reasonable to me.

 

[Mudsport96]

Soo what cam did you go with?

 

[blueinkd]

Just finished the torque sequence on the heads. Needs oil pump, timing set, oil pan and rear timing cover. May not get to drop it in tomorrow. Wife is traveling out of town and need time with her! Giggidy Giggidy goo!!

 

[blueinkd]

DOES anyone have a quick pick for reference of the studs that hold the bellhousing to the engine. I know my buddy disconnected all of that back there so I'm going in blind for the reassembly. Probably not difficult but a reference would be handy.

There are several grounds and wires hanging back there. Unless I'm over thinking it and they are just ground wires. I know the oil pressure and cam sensor connectors for sure .

 

[iamdub]

DOES anyone have a quick pick for reference of the studs that hold the bellhousing to the engine. I know my buddy disconnected all of that back there so I'm going in blind for the reassembly. Probably not difficult but a reference would be handy.

There are several grounds and wires hanging back there. Unless I'm over thinking it and they are just ground wires. I know the oil pressure and cam sensor connectors for sure .

This is from my '08/GenIV. But it's what I have:

IIRC, there aren't any grounds on any of these. The only ground back there that I can think of is the braided one from the firewall to the back of the left/driver side head. Yes, the labels are chicken scratch. I can decipher them if you need and if they're even relevant to your LM7.

 

[blueinkd]

This is from my '08/GenIV. But it's what I have:

View attachment 401765


IIRC, there aren't any grounds on any of these. The only ground back there that I can think of is the braided one from the firewall to the back of the left/driver side head. Yes, the labels are chicken scratch. I can decipher them if you need and if they're even relevant to your LM7.

Much appreciated!! This definitely helps but I was more interested in the wires hanging back there. Thing is my buddy worked on that back part and removed the bellhousing and I don't like the feeling of going in blind. Really I haven't taken a close look either so I may just be over thinking it.