Estimate on Frankenstien Build Please....

[TSFR]

Hey Guys,
First let me say I am a complete newbie when it comes to engines and GM's in general. I recently purchased my first GM truck with the intention of pulling a trailer with 4 wheelers on it or whatever else I wanted within reason. 2005 Tahoe PPV and I LOVE this thing! Its clean and currently has 137k on it. It has the 5.3 flex fuel motor with a 4L60E transmission running 3.73 gears.



The transmission is getting slow which was not a complete suprise. I'm buying a Hughes Performance 4L80E (25-1) from a friend that is currently still mated to a FI 383LT motor (for sale). That was going to present a few challenges like a wiring adapter, new flex plate and a ECU flash not to mention the driveshaft needs to be shortened and the rear crossmemeber needs to be fabbed up a little anyway.

So I had to tell you all this so you understand what we are starting with in the first place.

Tonight I am picking up a complete (I beleive LQ4) 6.0 out of a 2005 Silverado 1500HD which came with a 4L80E originally attached to it but not included. The computer and wiring harness are both included. It had 104k on the motor before it recently got t-boned and totaled.


Last night I paid for these:
Trailblazer SS intake manifold with TB


Yellow spring from trailblazer ss with 32,000 miles


-2006 tbss cam (three bolt) (204/211 .525 .525 116)


SO.... from what I can find the stock motor is "supposed" to be 300hp and 360tq. We are thinking we are going to add the cam, springs and intake with the TB.
POSSIBLY add the springs to my current 5.3 heads to up the compression from the 9.5:1 to what we think is going to be 10.1:1 maybe? Not completely sure on that but it would be after the initial build....probably.

Any ideas what we are looking at hp and tq wise?
Will the TBSS throttle body plug into the 6.0 computer with no problems or will it require an adapter?
Any pitfalls or traps we should be aware of?

And lastly, does the idea of swapping my current 5.3 heads over sound like a good idea and should it just happen in the first place.

Sorry for being all over the place with this. At worst case it should be entertaining to follow

[Botlfed]

no you will need a TB adapter, and no dont use the 5.3 heads on the 6.0

[TSFR]

no you will need a TB adapter, and no dont use the 5.3 heads on the 6.0

The TB adapter is the plug adapter right?

The thought is the 5.3 heads will raise the compression back up from the stock 9.5, is this not the case or are we missing something? Is there a reason to not use the 6.0 heads?

Sorry, just looking for an explaination so I might be able to learn why or why not to use something.

Thanks.

[jansen]

The 5.3 heads have smaller valves and don't flow nearly as good as the heads you already have nut the 243 castings are just like the heads you have already but have a smaller combustion chamber to raise your compression without sacrificing flow.

[TSFR]

The 5.3 heads have smaller valves and don't flow nearly as good as the heads you already have nut the 243 castings are just like the heads you have already but have a smaller combustion chamber to raise your compression without sacrificing flow.

Thanks! Thats good to know, I didnt really consider the valve size being different. I thought they would be the same for some reason. 317 castings are on the 6.0 now.