IIRC, the iron heads are the exact same as the 317s spec wise. I'm not as familiar with the lq4s as I am the 5.3s. I do know in 2002 the 5.3s had an pcm upgrade that GM equated to the increase in factory rated HP. In 05/06 ish the 5.3s got better rods and efans and jumped the rating up again.

If the lq4 ratings changed through the years from similar changes then I wouldn't be that worried about it. Bore, stroke, compression, and displacement stayed the same. Although, i would prefer aluminum heads. I just got this because i got a deal on it.

 

Hang on to that rear end or sell it to some one on here that could use it. It can be converted to Six lug.

Those are nice Donor trucks for Hydroboost conversion as well.

 

What do the rear ends usually go for? I'm pretty sure the rpo codes read 3.73. The hydrobost was stripped from it unfortunately

 

The Iron Heads maybe the same in terms of flow but they add weight and don't dissipate the heat as well as there aluminum counterpart. They will preform just fine on a budget set up and you won't notice the difference.

As far as the 4.8/5.3 the PCM/ECU was changed in 2001 and continued into 2002. This is known as the 411 PCM. The PCM/ECU had nothing to do with a horsepower increase. In fact the PCM/ECU hardware is very similar to the 99/00 unit. The major change was in the OS.

In the Silverado Line up the PCM/ECU service numbers were as follows.
99-00 had the 09354896 PCM/ECU
01-02 had the 12200411 PCM/ECU

You can swap OS between the 2 and you won't notice the difference. The later OS in the 411 PCM/ECU has more tables that provide more control within the tune.

If I am not mistaken there was a very small change in the camshaft and some changes within the tune that give it a few more horsepower over the years.

 

Depends on who is buying, selling and location. $200-$300

It's a 14 bolt 9.5 And it will bolt right in the 99 up chassis.

You need 6 lug axles from a 88-98 4x4 9.5 and some spacers to mount the 1500 disc brakes to use with the 6 lug axles on that rear end.

The New Axles can be had for about $250 or less Shipped to your door.

I had spacers made locally and the guy charged me $100. It may seem like alot but this was a 1 off set and you have to factor in time and material.

I could probably also get away with using a thinner material. Also If I was buying material in Bulk and having a production run made the cost would go down to nearly 1/2 that. Unfortunately there isn't enough Demand for the initial investment to do a production run.

 

A little update:

Got the 6.0 and 4l80 out of the donor truck


Motor and trans were nasty


Found that the driver side exhaust manifold had been off before. The exhaust manifold bolts were broken off in the head in the front and back.


Engine separated from trans


Got the trans cleaned up. Alumakleen does wonders


Started cleaning the motor but didn't finish. Got to get a puller for the harmonic balancer.

 

Another little update.

Been cleaning stuff for a week, and it seems like I'm barely making any progress. I did get my cam swapped and my HD timing chain on. Going to have to get a new o ring for the pickup tube tm. Here's a pic of the motor currently:



I'm still trying to figure out what I'm going to do for the trans wiring. Is rather do the 60e tune, because I will not have to perform a segment swap, but I cannot find much information on how to do all the wiring.

 

There's a thread on ls1truck.com that goes into great DETAIL on everything for the 4L80 swap. I'll try to post a link up.

 

Please do!

 

Here ya go...

How to 4L60E to 4L80E trans swap