I am wanting to do some work on my 99 3.9 once the weather gets warmer, but i want to do alot of research, and find the best options before i even begin.

first off, i do plan to rebuild the engine, im planning for the worst case scenario, where id have to replace everything, but i want to strip it down, clean it up, and rebuild it, im wondering what anyones suggestions are in terms of maybe getting oversized pistons, and boring the cylinders a bit. or maybe shaving the head a bit.

i would definitely like to get some more hp out of the truck, but i mainly want to get a good rebuild done, so it will last a long time.

there is nothing currently wrong with it, minus what i think is a sticky lifter, however,m i have plenty of time in the summer, and i want to get it done, so nothing comes up as a big surprise, so "leaving it alone till something happens" is not an option,. especially the fact i dont have agarage and working in winter is aweful.


anyways. aside from rebuilding the engine, i was also wanting to look into exhaust, i think it has a magnaflow muffler and tip, not too sure, havent touched it since i bought it, but it does sound nice and growly. what i want to do, is make a second exhaust up, running down the drivers side, for a true dual exhaust, the problems i know this will bring is how will the o2 sensor handle that, could i just throw in a new pipe on the drivers side, and block off the hole at the Y on the passenger side and have nothing to worry about?

also, not a necessity, but some friends want me to look into a charger of some kind, i have to admit, doing a rebuild and throwing a supercharger or turbo on it,m would be pretty sweet, but as i am doing the work myself, and as i am limited with what i want to spend, i dont want to get too eager with stuff like that.

anyways, if anyone has tips for me before i get into the work, that would be great.

(i did do some searches on the forum, but there are so many threads with very minute things regarding this, i just want to get it all in one big topic)

 

Really if you plan to drop that much money into a v6 your better off going a v8. All you need a pcm and engine harness. You can keep all of your sensors and stuff. If you have the 44re or nv3500 you should really consider the 5.2. A big step up from the v6.

 

thats what i was thinking too, however i have an ax15, so i would need to come across a transmission as well. one problem ive heard though, is that the 3500 is incredibly heavy, the ax15 feels like 50 or 60 lbs, and from what ive heard, the 35 is quite a bit heavier.

however that leaves open the exhaust still, however i go about this project, i would really like to have two seperate exhausts, im just not sure how the computer and o2 sensors will like that they arent seeing as much exhaust coming out.

 

Not sure of the weight of the two of them but might be able to find a engine and tranny for sale. You can throw a cam,tuner and throttle body on the engine but your still not going to be gaining a lot of power. Imo the money guys spend on a v6 is pointless why not throw a v8 in there. Im just sayin ok you would need a engine and tranny, couple bucks but if you look at that vs modding your 6 you would be about the same power at least with the 8 you can go way past what the 6 could put out. You can do true duals if you like not sure how that works out with o2's tho. I've never heard them on a v6 so not sure how it would sound

 

If I were to dump money into my 3.9, this is what I would do:
-bore block .030 over
-deck block .010
-deck heads .015
-port and polish heads with a 3 angle valve job
-open the intake valve to 2"
-get a cam and plenum from Hughes
-1.7 roller rockers
-a V8 throttle body
-headers
-get a stage 1 intake (also found at hughes)
and lastly, when the motor is back in the truck, get a SCT tune and call it a day. As stated though, by the amount of time and work and MONEY that you would have to put into a 3.9, you would be money ahead, and power ahead by dropping in a factory V8, adding a set of headers, a cam and a tuner.

 

i think thats what ill end up doing, if i can find a low km engine/tranny, ill throw em in after making sure the seals are good and stuff, thanks for the input guys