Camshaft

[westsidek20]

Anybody running a "comp cams Xtreme 4x4" on their set up?
Dont know what to get, im building a 383 on my K20, its not going to be a racing engine, just a fun weekend truck with some offroad action, by that i mean i do want to feel the power when i press on the gas, the cam i have been looking at is...
Lift: .462''/.480''
Duration: 262°/270°
RPM Range: 1300-5600

Will that work for me?

[frotosride]

The only real issue i initially see with that cam choice is the operating range. Yes the upgrade will give you a boost in low end troque but if you have an automatic then using that cam may mean changing the converter to a slightly higher stall to ge the cam operating in it's rpm range. I'm in the process of building  a 383 as well and using an xtreme energy cam as well k12-242-2 it has a slightly longer duration and lift and with that it raises the rpm range to 1600-5800 which is just a little too much for the stock converter in my 700r4.  You may be right on the edge of not needing to upgrade but if you have a manual tranny then go for it.
Most important thing is make sure you get new lifters with the new cam and break it in properly...I cannot Stress this enough or you will be dis-satisfied with more than just the swap.

[westsidek20]

Ive been really cautious about picking parts and reading many articles about the subject, and i found an interesting article that gives some suggestion for a street performer engine and they suggest a cam starting at 2200 RPM and using a performer stall converter. I liked what i read and found the thumper cam kit K12-600-4 works from 2000-5800 RPM.

[frotosride]

Yes those cams are for street cars but what they mean are street legal drag cars. You don't want your rpm range that high in that truck unless you plan on getting a higher stall tq converter and larger ring-pinion in the rear and front if you have 4x4. With that set up you will need an intake manifold that will allow you the same rpm which will most likely be a single plane. I highly recommend you take it down a few steps because you said your self you weren't looking for a drag truck so moving your power so high up the rpm band is a waste for you. Your truck is going to shift before you ever reach your peak power/rpm and your lower rpm torque and hp will suffer. I promise you that if you go with this you will be disappointed.

[westsidek20]

Darn, I'm in the middle of this now, i have already ordered an intake manifold specific for this cam and a stall converter, also headers.
i already have Big gears on the 4x4 since its a 14 bolt FF. I went with the 2000-5800 RPM as a little above normal, because other community members were talking about using even a higher RPM cam, between 2200 and 2800, but it seemed to much for me, i wish you luck on your build and i will keep you posted on mine. 

[Psycho71]

I went with the extreme energy comp cam (262 grind) in my 350 rebuild for my k20 burb, and I like it. It does OK driving around on the street, and when I poke it in low range 4wd, it works like a champ. Had plenty of torque to snap the u-joint in the front axle the first time I romped on it. I used a HD low stall converter in my th400 trans (per my trans builder's advice), it idles fine in gear, and poses no real problems overall. My 350 is right around 9.5:1 CR, and has a performer rpm intake with a 4hole spacer under the Street Avenger 670 carb. Driveability is good, and I even get a few compliments at redlights because the cam lopes a little bit. My burb has 3.73's in front and rear, with 35" tires on it. I will eventually change to 4.10's or 4.56's, but not in any hurry at this point. Right or wrong, that's my experience. Not sure how different the 4x4 series cams oare from the XE's, so that might a difference.

I am considering a 6.2 liter diesel swap, but that is from strictly an mpg point of view. This engine would then go into another truck i have. But that's another subject all together.

[Engineer]

On the subject of cams, if you ask 10 people you get 11 opinions.......

Here is mine. On a 4x4 you want torque. You may try a cam in the 260* range, and go with a 1.6 ratio rocker arm. More lift with less duration will add torque. Just be sure to check for valve train interference with the 1.6.

Also you are building a 383. Good. More cubes the better. More cubes will hide duration, and thus help give back some torque than say what a 350 could do.

Just remember with your heavy pick up truck, your stock converter is going to max stall around 1800RPM, so anything aimed below 1800RPM is a waste.

If you go with your first choice you will do fine IMHO. Unless going to a stall, I would stay away from the components that start at 2200RPM.

[westsidek20]

I'm aware that one thing leads you to another, 2000+ cam, needs 2000+ stall and RPM intake, and that takes you to needing headers.

@Psycho71 I'm worried about snapping my u-joints and my Gov Loc.

Once i get all my stuff i will make a post about it and i will try to get a video in also