I am getting ready to have a new (remanufactured) 3.0 installed in my 93 4x4 DLX and I am thinking that I will have Doug Thorley headers installed also. I know that many would do the 3.4 swap, but I need to stay on a reasonable budget, so I am sticking with the 3.0. I am looking for anyone with information on what I should use from the headers to the tip. I am not a mechanic, so I am going to have to depend on an installer for this work. Any advice on what I should use would be great.

 

2.5 inch to the back, nice hi-flow muffler (Borla, Flowmaster, Magnaflow) and no cat if you can get away with it.

 

Just get a high flow cat instead of ditching it. Theres no point in polluting the air even more just for a little extra power that you wont even notice.

 

Not so much worried about that as the cost of buying one.

 

It's just a couple hundred bucks.

 

No cat ftw!

 

I would definitely put a cat in. I had a set of the Downey headers on my old 3.0 and ran a hollowed out cat and a Doug Thorey cat back. It was EXTREMELY loud, and, after I wrecked the truck and got something new, I realized it was way too high flowing for that old motor. Having a exhaust that flows too freely is tantamount to burning up valves. The headers will really open that pup up, but keep a little back pressure in there. I'd recommend a stock replacement cat, a good 2.25 cat back, capped off with a good turbo style muffler. It will give it a good tone, flow well, and not be too loud.

 

Do you have smog rules in your county?

 

250000 yota is right no cat not enuf back presser i had not cat on mine it was really loud and way to free flowing lose some low end power and the 3.0 dos not have much power to spare! so i redid mine and put a hi flow and a cheery bomb stly on mine i like it sounds great not too obnoxious and i did like my turbo stly muffle i had on too!
heres mine

i put a turn down on the end so it would not blown right in my back window

 

Thanks for all of the advice. It has been a while in deciding to spend the money on my truck, but I made the decision this evening and I should have the processs started in about a week. Remanufactured engine, new clutch, radiator and exhaust. After having the truck for the last 19 years, I guess it will be worth it to have it back on the road.

 

Also, to keep back pressure I suggest going with 2.25in pipe (vs 2.5in)... 2.25 is the biggest you can go without noticing the loss of back pressure (from what I've read).