All the more reason to run it for the time being while keeping an eye out a good 6.0L.

You don't want to get stuck with something that needs work.

 

So thinking about this last night- if I got a lq9 and keep it all stock - (wife will be driving it need reliable) the stock 5.3 exhaust system might not be big enough- I don't want to create to much back pressure and hurt the new motor

 

A stock 6.0 will be just fine with stock exhaust.

 

Cool thanks

 

Giving a update: got the truck home this weekend put about 150 miles on it so far, oil pressure is steady 40 psi cruising- it was getting (on the dash) 20.8 mpg on the eway doing 72 mph - city is about 17

Not to bad - going to change oil again Tuesday to keep flushing it. I have two quarts of trans fluid in it.

 

Pour a can of Seafoam in the crankcase and let it run for about 30min.

Have you pulled the valve covers off to see if there is any buildup/sludge? this will give you an idea of how the previous owner took care of it.

On mine, with 154k, the top of the head is clean enough for you to eat off of (minus the oil of course). I change the oil in the truck about every 3500-4k, religiously.

 

My shop has a camera I ran through the filler neck so I didn't have to remove it... I was shocked on how clean it was I was expecting sludge like the old 350 tbi motors ...

 

Sounds like you're in the clear for now. I love using tranny fluid in the oil to clean it out, works like a charm and is safer than seafoam. Because you can run trans fluid for hundreds of miles to let it eat away gunk and deep clean parts.

 

Well motor started puffing smoke when starting so I found the new donor motor- lq9 - figured I'd do head gaskets while it was out, and look things over

 

That's really clean inside. What did you use to clean it?