I am interested, but I actually live in Nebraska. I'll be working out of St. Louis for a few months. Its about a 9 hour drive to you. If I can swing down there with the Tahoe I could buy it all. With a good solid engine, I could swap cams.

 

Gotcha

 

Caprice may not have answered you with perfect manners but he was offering advise. You shouldn't attack for something so minuscule if you are looking for advise. He had a valid point. Anyhow, when you speak of breaking in a new cam, you should be aware that these are roller cams and don't really break in the way a flat tappet would. The cam swap wouldn't likely shorten the life of the short block. Castec head problems were limited to 706's and it was rare at that. These motors are super tough. Good luck to you.

 

Whoops. I saw Woodlands, TX..but that is KCS.

 

Half of what I claim I know is still more than you do or ever will if this is the attitude you want to take.
There was a time when I had the same poor ideas about how to make power, then I got a clue. I have made many mistakes and seen others make a lot and don't understand why people want to keep repeating them

You want to boost power on an OEM engine NA you are generally going to be looking at more rpm, higher compression helps too but you can't add much before needing to look at octane. Even small aftermarket cam options are going to shine most at higher than stock rpm levels.

I put over 300miles on my 5.3l truck today with an empty car trailer, even empty it needed more rpm to have towed well even in flat Wisconsin on the highway a 65-70mph. The 5.3l factory gearing is ok for the daily unloaded commute, start hauling and they need some gearing or some displacement to cope with the crappy gearing.

The 4200lbs Caprice was perfect for daily driving with 3.42 gears and a 27" tire, due to tire size that allows very slightly more rpm than a truck with 265/70/17 tires and 3.73, BUT the truck makes the same peak torque 800rpm later and weights more. Meaning they need gear to let the engine turn rpm, or they need displacement or boost to raise low rpm torque.

Bigger valves and such are going to be of modest at best value on a stock cam and even then probably only when DEEP in the pedal, otherwise that big 3" valve at the front of the intake is choking all the flow.

I want to improve performance on my 2005 5.3l truck and based on my EXPERIENCE 4.10 gears or a 6.0l engine are the best bets. I am willing to do the junkyard engine though and while capable of doing axle gears I think I can pull off a junkyard 6.0l cheaper and easier.

You are questioning the engine integrity and want a little more performance on 87 octane. Fresher LQ4 seems obvious.

I know none of this is what you want to hear but that doesn't mean it is bad advise.

 

There was a time when I was committed to making this truck more powerful. It was a primary vehicle. Since then, I've purchased a 2012 Impala LTZ, a 2009 Tahoe, and I have a daughter in college now. Beefing up the 2004 truck is not a primary objective any more.

I have to replace the heads. I may have to replace the engine. On the other hand, the current engine runs very well in spite of glycol contamination... Maybe I don't have to replace the engine.

If I thought it would work, I'd put stop leak in the coolant and run the engine until it dies, then replace the whole thing.

Buying junkyard parts only works when you have the time to do the work or you have a trusted local engine builder. At the moment, I have neither. I don't even have a junk yard within 50 miles of here. This is Nebraska. We have corn and tractors. It took a year to find a trusted basic mechanic.

As for your knowledge vs mine... we'll both believe what we want. I've never built an engine that didn't exceed my expectations. That's good enough for me.

 

I'm not concerned with the lobes. If I were, I'd just replace the lifters too. I'm concerned about mating the new cam's bearing surfaces to likely damaged cam bearings. When enough of the cam bearing surface is worn off, your oil pressure drops off, then you have a seized or damaged motor.

 

Although I agree that it's nearly pointless to put better heads on a motor with a stock cam, I will point out that last I knew Thompson Motorsports sells stock rebuilt 799 heads for $700. They aren't listed on there website so you would have to contact them to find out for sure.

 

How can the Castech heads be identified externally?
Have an 02 Silverado with 160k shes getting a little tired

Wish I was closer to Tx Id grab that lower mile motor/heads from you

These engines still get a ton out here, 6.0 (what I really want) are out of sight.
Would like to slowly put something together to freshen this old battleaxe a bit.

 

Is there light colored sludge in the oil filler tube or cap? Is the engine eating antifreeze and/or oil? Are fluids seeping out through the heads? You've got bad heads, likely castech heads. There is no accurate way to tell without taking the valve covers off.

 

I'll call them and see what they have. THANKS!

 

Nothing sludgy yet but I keep an eye on it valve covers never been off it

 

Castech are mostly or all 706 casting. 862 casting are not Castech.

(number on outside end of head; quite apparent)