From my personal experience with my wife's truck which is a 03 2500hd I put a Gt2-3 cam in with p&p 862's with 2inch valves and lt headers and it is nite and day difference from the 317's. Better gas mileage and it hauls butt and I didn't even touch the stock torque converter

 

All good info above.

I used a tube and fin style, LARGE, trans cooler and it sucked. Get one of those nice bar and plate style like redxray posted up in the second pic

My tube and fin one was just like redxray's he showed in the first picture, but larger than that, it was the "one for an RV" they said when I bought it. And I was pretty much always over 200 degrees even with the radiator bypassed. Which I would also do.

 

I was actually looking at the Tru-cool 40k. I currently have a thermostatically controlled pusher fan on the factory auxiliary cooler with the fluid path still in the OEM configuration. Even so, it regularly hits 200 degrees when just commuting. Although, part of that is likely the highly worn transmission.

I like to have a dedicated trans cooler fan because I have e-fans on the radiator in place of the mechanical fan and that seems to allow the transmission to run hotter.

Is there a solution for mounting a pusher fan to the 40k cooler? Or is this cooler effective enough to not need a dedicated fan.

Inversely, when it's extremely cold out, it's already hard to get the transmission to even get warm enough to register on the temperature gauge. Does anyone have experience with the cooler bypass thermostat?

Just to clarify, your suggesting deleting the OEM radiator-integrated trans cooler from the fluid path altogether?

 

With a stock thermostat, the radiator temperatures are in the 190 - 210 degree range. You would be limiting the effectiveness of the external cooler. You shouldn't need a cooling fan with the 40K. I'm located in SC and on cold days my gauge doesn't move from the lowest reading on short drives. If you're in a cold climate and don't mothball the truck for the winter season... I'd say buy the thermostat with the 40K.

 

Thanks for all of the awesome info.

-Conclusion:
--Phase one(Very Soon):
---Performabuilt Stage 2 4L65E (tweaked for DD and towing)
---CircleD HP 300mm, 2200-2400, billet front cover
---Trucool 40K (bypass radiator cooler)
---Thermal Bypass? Maybe
---Full rebuild of NP149 AWD Transfer Case
---All new U-Joints
---New oil cooler adapter gaskets and new lines(the originals are leaking)
---Hydroboost Retrofit with braided lines and new power steering cooler
---EFIlive tune
(The truck has 240k Miles on it so I'm considering doing a rear main seal and oil pan gasket while I'm at it. They are not leaking so is it worth doing or should I leave it alone?)

--Phase Two:
---706 heads(level of machining still undecided. Waiting on pricing)
---TBSS Intake with corvette FPR
---Cam and Springs (still undecided considering the high stall converter and I need to look into the dynamic compression numbers a little more.)
---Upgraded Oil Pump?
---New Pushrods?
---New Lifters due to age?
---New Timing set due to age?
---Long tube headers? Maybe.
---Retune

 

you add a cam to the mix and start getting aggressive good change they will leak the rear main while its apart i would for sure

 

At 240k I'd replace every seal I can while its apart.

 

I would do the oil pan gasket and rear main if you're down there and have it apart. You should be pulling the pan anyway to make sure you do the oil pump and pickup tube properly, aka so you don't risk tearing the O ring. The oil pan gaskets all go bad at some point so if you don't do it now you will before too long anyway. So for several reasons pull the pan and do the gasket.

The rear main is easy with the trans out, and best to do with the pan off, if you're pulling the entire rear main plate, which you need to because it's a good plan to replace the plate gasket too. I have done a ton of them and have all the alignment tools. In all my years I never had a leak after doing a LS seal, even not using the alignment tools until one time I did a rear main about a week after doing the pan gasket. I used a entire new rear main assembly from GM (comes with the seal already installed in the plate with a new gasket and bolts, and when I slid the plate on the back of the motor it knocked the rubber off of the oil pan gasket in the rear. So do the rear main with the oil pan off to help avoid issues there. It's pretty much impossible to put the rear main plate on with the oil pan gasket in place and not damage the oil pan gasket.

You can do a new barbell while you have the rear main plate off. Yeah the list just keeps going lol.

And don't forget to reseal your cam sensor with a new o ring while you have the motor apart. They leak bad and it's common. They leak all in the bell housing and most people mistake the cam sensor leak for a rear main leak. It's pretty damn annoying when you misdiagnose that one lol!



There is a fairly easy way to align everything and I have a few tricks from doing so many pans on LS trucks. I have an excellent method for aligning the pan if the trans is still on. Without the trans on its easy to line up the pan with a straight edge on the back of the block. The front and rear covers are a bit of a pain but you let the seal center itself on the crank and then tighten the bolts and you should be good there.



Edit: I agree. I would replace every seal while it's apart. No reason not too when you're that far in. And you'll be pissed if there's an issue after it's all together.

Oh and another don't forget... get some new steam pipe seals from the dealer while you're getting parts together. You always realize that nothing you bought came with them right when you're in the final stages and an hour or so from running it.. which means you always say **** it and reuse them and run it.. and then wish you would have had them during the build and put in new ones.. Don't ask how I know

 

will this same set up work with Lq9 & have ptv clearance.

 

No problem you can even go with a larger camshaft if needed/wanted with the LQ9.

I'm running 231/234 .629" .615" 111* LSA with no issues on a LQ9