Whether you get the NAPA or the Donaldson filter, make sure it has the mesh on the inside of the filter to prevent it from collapsing.
Another option is the Amsoil filters you see in my signature. I've never ran a 6637, but I love the filters I use.
You definitely want to spend the money on a decent downpipe. They are pretty cheap. Also, while you're doing it, look into gutting the exhaust back pressure valve (EBPV). Its not something everyone wants to do, but I don't miss mine even a little.
Mine is already straight piped turbo back. But my exhaust is 3 inches, is that stock?. I know I need to get a bigger one. What size downpipe should or can I gwt without cutting anything? Also where is the EBPV?
I painted the pipe, but that was a personal choice.
Where did you get the pipe? And isnt that filter more prone to get dirt in the air versus the stock one? I drive 10 miles of gravel just to get to the highway from my house. So is this filter ok for that?
The air filter and pipe are both from NAPA. I've had no problems with this filter. This is the same one that some bigger trucks use, as well as some tractors and other industrial / heavy-duty applications.
I've driven on gravel and dirt roads, through heavy rain and snow, through "puddles" and have had no problems. I recently replaced my filter after driving for about three years on the previous one. I will not go back to the OEM setup and I have no interest in using a K&N or other setup. This setup works fantastic.
Ok, my question from before, Mine is already straight piped turbo back. But my exhaust is 3 inches, is that stock?. I know I need to get a bigger one. What size downpipe should or can I get without cutting anything? Also where is the EBPV?
EBPV is on the turbo exhaust side where the down pipe is attached to the turbo its the 2 inch piece that protrudes off the turbo and has a open/close valve inside it if u don't want to use it u can just unplug it (turbo intake side bottom) or u can do the exhaust break mod !
and i think that the stock pipes are 2.5inch not totally sure here tho.... and from what i have read 3 inch is as big as u can go without modding the
side wall/firewall.... but it is still a bear to get it in without pulling the EBPV off the turbo
the EBPV is used by the engine to quicken the warming of the motor (cold/winter) and opens back up when motor reaches a warm enough temp on warm days like now itll close for a very short time then open back up its not really needed and alot of people "delete" it to know how to do this just search EBPV delete on YouTube!
Correct info on the EBPV. I've had mine deleted for 5 years and don't miss it. This winter when it was -20, the truck had no problem staying at operating temp.
The stock downpipe is an obround shape. I'm not sure of the size. The rest of the stock exhaust is 3.5 in. You definitely want a 2 piece 3 in downpipe for easy install. Its adequate for most people's horsepower. I recommend diamond eye. You should be able to find them for less than $150.