So I have a 99 Durango with the 318. Mods, k&n cai, msd blaster ss coil, 8mm wires, helix tb spacer, ss headers, straight pipe exhaust with hi flow cat, superchips flashpaq on 91 tune, and most recently hs 1.7 roller rockers. I ordered the rockers because of all the good things guys on here have said about them. I got them, put them on and... no difference in performance or mileage whatsoever. Only thing they did was give it a helluva smooth idle and smoother throughout the rpm range. No extra hp, tq, or mileage. Did I do something wrong? I reset the pcm when I installed them and they have about 500 miles on them? Or is this just my luck?

 

You have some mods working against you, the exhaust may be opened up too much, alot of people say they lose a little bottom end with a K&N Cai, and the TB spacer is a paper weight. And the MSD coil really doesn't do anything over the stock coil, not that it's hurting anything though.

 

The thing is I didn't loose anything either. It's exactly the same. The spacer was really cheap so I figured why not, and I thought it would be best to list all my mods.

 

The other items may be defeating the purpose of the rockers is what I'm trying to say. I'd lose the spacer first. And headers with just a cat and too big of pipes will hurt quite a bit too. And thanks for giving the details of the mods you've done, it's important to know. I'm sure you'll get better and more info from the guys on here. And just for S&G's , install your stock air intake if you still have it.

 

You sure you actually received 1.7's and not 1.6's? Might want to pull a valve cover and check with a dial indicator.

 

I'll pull the spacer in a little bit, I have some scott shop rags, think I could wrap the filter with those a few times because I lost the stock air box a long time ago. Arde- I was just wondering the same thing, I looked for the package this morning but I must have thrown it, the summitracing sales receipt says 1.7 roller rockers with the right part number but they could have sent the 1.6's by mistake, guess the only way is to pull the valve cover.

 

The K&N is only a small part of the big picture. Depending on the size of straight pipe used, I think the exhaust is more of an issue. Does the number on this package look familiar?

 

Exhaust is partially stock, headers going to the y pipe with the single 2.5 inch pipe straight out the back with a tiny hi flow cat, same setup as stock past the headers except for the smaller cat and muffler replaced with a pipe. I honestly don't remember the number on my package Your number is the one I ordered but I can't remember what was on mine and I'm kicking myself for throwing it away right now.

 

As you can see, the flap with the part no is folded over, the only pic I took of the package.
opps, pic was too big

 

here it is