Will a 04 avoache radiotor fit

These body-on-frame Chevy GMT800 trucks use many of the same parts, even the transmissions at least mechanically. The chassis parts do not carry, but parts like the radiators tend to carry over in most cases (still has some small variation as well, so double-check).

As a general rule you still need to check, but you can often trust but verify with GMT800 platform trucks (Silverado, Tahoe, Escalade). These also predate the complex engines where we can't remove the garbage like DOD and cylinder deactivation with Corvette LS heads, normal lifters, and a Corvette camshaft/race camshaft when it broke as it always does on these and finalizing the death of that garbage by tuning the engine based on the stock tune (if it's baked into the tune) or disabling it in the coding.
If it weren't a pain to do because a full tune is needed we'd solve the problem with these 2007 DOD GMT800s using LS3 engines since the LT engine is based on an LS-derived design. Then build them up to handle some tuning and build a nearly bulletproof engine for these GMT800 trucks. Potentially build it out to be a sleeper by sticking a raw LS3 without any of the eco junk on it since the MPG will be horrible either way by exploiting that the engine was built for high-speed runs and tuning. I would trust a Corvette engine to take some abuse given how some people tune them without any issues; if you can throw a tune that boosts the torque to pull a 200mph run, you have an engine that's built for speed.

You can't do that on the modern ones where this garbage is baked into the design and not bolted on (except the 2007 Silverado "Classic", which kept the legendary GMT800 platform going for rental fleets until 2008) where your "oil consumption rebuild" is LS3 lifters, an LS3 head and a camshaft from a Corvette (or a racing built camshaft) with a tune or feature delete to disable the DOD you deleted. The infamous Obama bailout of 2008 ruined what GM built (and they never recovered) because he pushed GM for higher MPG numbers at the expense of what made the GMT800 good :-(. Hint: There's a reason these old GMT800 trucks regularly have 200k+ miles, and it's not a concern to any of the owners of the vehicles. These things are really that good to the point people buy them with 6 digits on the odometer and look at it like a number like Toyota and Honda buyers. These new GM trucks are garbage; small turbo engines in big vehicles (short lived before you have to replace the engine) that cannot tow anything heavy to save their lives, V6 NA engines which struggle with heavy towing and the "New GM" Colorado (2007-present) with known problems with engines blowing up in the low 100k mile range; or near 100k miles.

These "Old GM" trucks are known for poor gas mileage but also have near bulletproof engines and trannies that just run for years when you remove the garbage like DOD and disable cylinder deactivation at the ECU level. As long as they aren't rust belt messes, they run forever when the owner does the engine modifications needed, swap the rear main seal (a common issue with "old GM" GMT800 chassis vehicles), and swap the stock trans for a built 4L60E if it ever needs to be replaced as the stock tranny is on the weak side with the gas engine (note: Not an issue on diesel "HD" trucks; these have a much more robust Allison trans with a pre-emissions Duramax engine)

If I had to find a truck that was built to last I'd buy a Duramax GMT800 for the Allison trans or a 2500 gas GMT800 for the much more durable 4L80E or a Toyota.