Well im about 3k away from 200k miles and the tahoe is VERY tired. I have a whole list of things i would like to fix but the motor and trans are on the top of the list.

The motor:
I haven had a chance to pull the heads or the bottom pan but I found metal shavings on the dipstick and on the pan magnet. Ive been at school for the past 4 months while my brother has been driving my truck so i have a feeling he never had the oil changed and he put a solid 20k on it. The check engine light also came on for the knock sensors again the day before i left. Tried to pull parts together but couldnt find anything. I dont know how much damage was done from leaving it like that but the truck has a very hard time turning over. Usually takes 2 or 3 times before it finally starts, hot or cold.

I really dont want to waste my time with a old motor so im looking to swap in something newer. I was set on finding a low mile LS1, strapping some bolt ons to it but after doing some research on here the LQ4/9 looks like the better option. I really want to try to use as much as i can.

So, i have couple questions:

I know that I cant use a 99-02 6.0 because of it not being able to pair with the 60e which is fine but for all the other motors, is there anything else i need to mate up the block and trans. Im going to be running a trail blazer stall if that helps.

If the block comes with no heads will my 865s work properly, i know the LQ4/9 have different compression ratios and that a different set of heads will effect that. Is it something that i can tune out?

Im pretty sure i have the original injectors if not i know they are factory. Im not looking to buy new injectors since they are a but pricy so will i have to increase the flow rate in the tune?

Also since the motor will be already out i may throw some mild things in there like LS yellow springs, ls6 or something similar, NNBS intake. We'll see


The trans:

My transmission has been through hell and back towing a 8500lb boat so im sure its gonna be nasty inside. Since the motor is in "safe mode" i havent been able to tell if its slipping at the top of the rpm range. Full throttle 1-2 and 2-3 shifts are VERY rough, the truck literally lurches forward. I have had trouble with slipping in the past so i increased the line pressure and it all went back to normal. As time went on the slipping was replaced with harsh shifts. Partial throttle is alright, shifts are harsh but not as bad.

I am not looking to swap in a 80e being that my budget is a bit tight. Im looking for maybe a upgraded rebuild kit. Of course i wont know until i tear everything apart but i have a feeling its bad.

Is the difference between the 60e and 65e just internal?


All of the work will be done at my buddies shop down the road so im not worried about labor charges, im going to take as much time as it needs to make sure everything is perfect.

Thanks again!

 

If i were yo id keep my eye on craigslist or ebay till a motor and trans comes up cheap I picked up my lq4 for $400 local. I am not sure what kind of budget your on but Id buy a motor with heads because by the time you buy headbolts, gaskets, seals and springs for your old heads it will be alot more than buying a low mile long block. Id ask around about the 99-02s not working with a 60e because i thought it was only 99 and 00 because my lq4 is a 01 i believe and it bolted right up. Not for sure though.

 

It is only the 1999-2000 iron headed 6.0L’s that propose an issue with mating to the 4L60/65E transmissions due to the long style crankshaft, yet if one already had the engine in hand, one could also source a hybrid torque converter to mate the two together. No it can’t be done using factory style components though. Now if you didn’t already have the engine, I would say it would be best to source a 2001 or newer model from the start, with preference of using a 2005 or newer for having an engine with all the latest updates. All the updates didn’t just magically happen in 2005, they started a little each year prior, but by then they were all in effect, so if it all possible that’s where I would start.