I am trying to build a 350 to 500 hp chevy 4.3L V6. If anybody could help, whether it is a guide, manual, or experience to help me suceed in this project please reply.

350-500 is an awfully broad range to shoot for and a big difference in the way the engine is built. A turbocharger might be the best way to reach what you're looking for.

If you`ll recall the Cyclones they were fast, and they came factory with a turbocharged 4.3. With the right parts you could reach your goal, But first, you`d best find a crank that will hold together. If you look the journals are split on the rod throws, you`ll noticed the amount of material between the two is very thin. Likely around the time you reached 400 horses it would come unglued. I think it would support 300 ok. But if you want to keep stepping it up on power, piece by piece, sooner or later your gonna find the limit of the crank and it`ll break. I don`t know if anyone makes a stronger crank to honest with you, you could maybe do a search. My nephew and I had thoughts of building one to make around 300 to go in a 4x4 geo tracker, just to make a play thing for mud, we may get around to it one of these days as I already have most of the parts. You`ll need a set of vortec heads from a 96 or later Vortec 4.3, the prior heads are all swirl vane heads that die around 4000 rpm. Also don`t let the name "vortec" confuse you, the 4.3 always used the name, and many said so on the valve covers, but the Real vortec heads only came on the 96 and later vehicles. they, like there big brother V8`s, have the straight up 8 bolts bolt pattern. you`ll also need the vortec intake that matches from elelbrock. I have a set of these heads off a 99 model. If you find a set of these heads, you`ll notice the rocker studs are screwed in, you have to remove these and get some standard screw in studs to convert it to a adjustable valve train. Lastly, the real vortec engines are easy to spot in the junk yard, they have a ribbed cast aluminum oil pan. Lastly, here`s a link that will tell you much about the differences in the 4.3`s. I had to study these engines when I did the rebuild on the 4.3 in my pickup. I used a computer compatible isky hydraulic roller cam, edelbrock tbi intake, flat top pistons, I reused the junk swirl vane heads, I ported the intake ports and had necked down stainless valves installed, it has killer take off power, but falls dead at 4000 RPM due to the heads lack of flow. I could have used the vortec heads, but decided I didn`t want to do the custom chip party, as in most cases the guy making the chip has to sit there with a lap top to get all the varibles set that make it run best. There`s nobody around here that does that, so I left it alone, I am going to get a chip for it, but it`ll just be a basic upgrade chip.
http://www.s10forum.com/forum/f107/...-3-info-131868/ One last edit,,, if it`s the early non balance shaft block you plan to use, have it balanced. It should be balanced at a scale of 36%, I was told by a fellow member of this site to have mine to this spec and it worked out perfect, mine doesn`t shake and revs smooth. Also on the older non balance shaft engines don`t use the factory balancer, buy a aftermarket 8 inch balancer for a 350 chevrolet. These engines are known shakers, this is why a balance job is highly recommended.

Hot Rod Magazine built a pretty conservative N/A 4.3 and made 300 hp. My link to the article does not work any more, but you may be able to find it on their site.

This isn't the article I was referring to but it is worth 500 hp. Also the one I was referring to was from August 02.
http://www.hotrod.com/techarticles/...l l/index.html

How deep are your pockets?

Look at what some of the import tuners are doing, your goal is not unreasonable...but expensive. You should build a rock solid foundation and use forced induction. Doublevision gives good advice.

I'll say!!! You might also check the Syclone boards. Those guys are squeezing some serious power out of their 4.3's but like mentioned above they aren't afraid to pay either.

The HRM 262 // 4.3 v6 build mentioned above achieved 301 fwhp (engine dyno conditions) on a 270 cid (bored 4.3 v6) using ported factory swirl port casting iron heads, a very good exhaust, and a cam suited for a blower (the final build motivation). On the blower they made over 500 hp.

Engine build:

http://www.hotrod.com/techarticles/...uild/index.html


Using the blower:

http://www.hotrod.com/techarticles/...l l/index.html

well actually im want to get as much horsepower as i can and still drive it daily on the road. i'll probably completely rebuild the engine with pistons, crank, heads, cam, etc.

i wanna get 600hp out of a 2.2, and drive it daily. so i can get 35mpg going to work. and go street racing on the weekend. and i only have $2500 to spend. =

Wow, I can see you going far. Maybe he has big dreams but who are you to crush them?

Seems to me I remember a little turbo V6 Buick kicking the crud out of the other "musclecars" not all that long ago...and at 4000 lbs with all the creature comforts to boot.

is a real 500hp 4.3 far enough for ya ? i'm getting close.