Blown 5.3, Looking for 6.0, which ones fit?

[Matthew Jeschke]

I made a post before the post history got whipped out (can only find in google search). I linked it HERE

My 5.3L hydrolocked due to stuck injector and snapped a rod. My goal has been to swap it with a 6.0L. I'm finding plenty of 6.0L engines listed online. However, many say they won't fit a 2001 Tahoe? How do I know if the motor will fit? Is there a certain year of the LQ4/LQ9 motor I need to have?

I need a Gen III Vortec 6000. LM4 or LQ9
I'd LOVE a LS2 aluminum block but likely won't find that.

 

[iamdub]

If they're complete newer pullouts with intake manifold, etc., then there could/would be differences and why they'd list it as such. You can just swap your intake manifold over and it'll all be plug-and-play. You gotta pull the manifold off anyway to swap over those knock sensors and harness, anyway. The only real differences were DBW or DBC TB and return or returnless fuel rail. IIRC, the HDs had return style, which is most likely where a Gen3 6.0 would come from.

...After you resolve your stuck injector problem, of course.

 

[Matthew Jeschke]

Hah yeah for sure I need to resolve the stuck injector haha

Sent from my SM-A505U using Tapatalk

 

[iamdub]

If you can find one and fit it into the budget, aim for the LQ9. Better parts and mo powa. I highly recommend 93 octane only, though. Also, get one from an Escalade as it'll be a lot less likely to have been beaten on versus one from from a Silverado SS.

 

[Matthew Jeschke]

If you can find one and fit it into the budget, aim for the LQ9. Better parts and mo powa. I highly recommend 93 octane only, though. Also, get one from an Escalade as it'll be a lot less likely to have been beaten on versus one from from a Silverado SS.

There is something about the crankshaft being longer on some years? then the flexplate doesn't reach far enough to mount to torque converter?

Sent from my SM-A505U using Tapatalk

 

[iamdub]

There is something about the crankshaft being longer on some years? then the flexplate doesn't reach far enough to mount to torque converter?

Sent from my SM-A505U using Tapatalk

Forgot that detail. Yes, and it's resolved with a ~1/2" spacer (it's an actual GM part). Here's the deets: https://www.novak-adapt.com/knowledge/gm-crank-spacing

 

[Matthew Jeschke]

sweeeeeet thanks for clarifying that little detail.

The plan is to rebuild whatever I buy. Only problem is getting it to the machine shop. But with some luck, I can do the whole bottom end myself. Maybe whole thing w/o the machine shop. Just I assume these aluminum heads need resurfaced / plained when you pull them?

Also only difference I se between LQ4 and LQ9 are the pistons. Apparently the LQ9 has flat topmlm pistons which give a bit more power / compression?

Sent from my SM-A505U using Tapatalk

 

[iamdub]

sweeeeeet thanks for clarifying that little detail.

The plan is to rebuild whatever I buy. Only problem is getting it to the machine shop. But with some luck, I can do the whole bottom end myself. Maybe whole thing w/o the machine shop. Just I assume these aluminum heads need resurfaced / plained when you pull them?

Depends on how in-depth you wanna rebuild it. You could go all out and get the cylinders bored or just honed, which you can hone at home. I'd measure the bores to check for roundness, though. If you happen to get a low-mileage one and the cross-hatching is still strong and even, then machining wouldn't be necessary. You'll need a special tool for the cam bearings. If it were me, I'd spend the couple hundred bucks and let the pros with their special tools and equipment do all the cleaning, measuring and bearing replacing. The heads can just be cleaned and checked for flatness and get new valve seals at a bare minimum. But, it's always nice to have a cleaning pass on them to ensure a flat surface. Since they'll be set up on the machine for the cleaning pass, you may even entertain a light shave to boost compression, depending on your goals. Maybe nix the shave and get thinner head gaskets. Maybe have the shop minimize the lump in the intake runners and blend in the bowls for more CFM. This all depends on what you want out of it as a whole. I'm a fan of high compression (10.5+) on an NA engine, but this demands 89 or 91/93 octane fuel.

Also only difference I se between LQ4 and LQ9 are the pistons. Apparently the LQ9 has flat topmlm pistons which give a bit more power / compression?

This is half true. In the earlier years, pre-'04, the LQ9 was the same as the LQ4 except for the flat top pistons. Around '04/'05, the LQ9 got beefier rods and full-floating wrist pins. If you wanted to, since you're rebuilding it, the money you'd save getting a "boring" ubiquitous (and, therefore cheaper) LQ4 could be put towards aftermarket flat top pistons, making it an LQ9.


Built right, you can make an LQ9 an "iron LS2". The 80lb difference is kinda negligible and the overall cost would be less, depending on how wild you get with it.

 

[Matthew Jeschke]

Another thought I had, but I'm not sure if it's cost effective... Is to have the 5.3 bored out and sleeved for a 4" piston as in the 6.0. Then All I need are the heads, pistons, and camshaft.

 

[iamdub]

Another thought I had, but I'm not sure if it's cost effective... Is to have the 5.3 bored out and sleeved for a 4" piston as in the 6.0. Then All I need are the heads, pistons, and camshaft.

You can't bore a 5.3 that much. Safe maximum is 3.9 to bring it to LS1/5.7 size. Well, to be accurate, there are some super rare 4.8/5.3/6.0 blocks made for a short time when the foundry for GM was gonna make a one-size-fits-all block. You'll likely never see one in real life. Besides, you should be able to find a good rebuildable 6.0 core for far less than punching out a 5.3. You may need or want to have the 6.0 bored, so save your machining money for that.