Vortec L29 question

[Accrdwgnguy]

Just picked up a 1999 GMC Suburban, with a L29 454. Runs great and holds 45+psi hot idle with 201k miles on it. The previous owner appears to have swapped out the stock thermo for a 160 temp one, plus dropped in a K&N air filter. My main concerns are engine life and (of course) fuel mileage, so would I be better off swapping to a stock thermo and filter, or leave it?

[Montecarlodrag]

Stock thermostat will net you slightly better mileage but may not be even noticeable.
As long as the K&N filter isn't too oiled (to skew MAF readings) it's not a concern.

[Accrdwgnguy]

I may leave it alone then as the truck is still filled with Dexcool. I washed the filter and then put it back in dry as I couldn't find my can of KN filter oil at the time, I have it now so just a light mist of oil? I'm not sure if it's necessarily a bad thing to run them dry.

[Montecarlodrag]

K&N filters need the oil to function properly.

[lionelhutz]

To me, I believe the 160* is fine depending on your geographic area and the time of year you drive the truck. For the most part, you want the air temperatures to be above freezing to run one.

[Accrdwgnguy]

Ohhh well looks like I'll be changing it out before next winter then, as I plan on using it year round.