My Camshaft Intalation Guide
Update 3/23/05
My valvetrain seems to have developed a rocker arm noise. I figure it is probably something to do with my 100K mile old lifters, and maybe not having an adjustable valvetrain. I will be upgrading with the following parts
Comp pro magnum rockers
1317-12
Comp lifters
850-12
6 sets of arp conversion studs
8mmX1.25 bottom, and 3/8" on top
134-7221
Either some shorter rocker nuts, or some taller early '90s valve covers off of ebay
Here are some pics i took of the clearence on the valve cover, and on the head. The stud is about .25" bellow the sealing outer rim. Don't mind that dirt on the pushrod, hehe.

end of update

I recommend a Haynes or Chiltons manual for torque specs, and a step by step. I have the Haynes, and it doesn�t explain the newer intake manifolds terribly well.

If you have never done any thing like this before, I recommend that you have someone help you that know kind of what they are doing. Expect it to take 4 days or so if you have little experience.

The Heads
On both we used the standard 260AHR without any regrinding. What people are referring to when they talk about regrinding is the Retainer to valve seal clearance. On the vortec heads, this dimension is at around .480�. When I did it last month, I actually measured the clearance and I found that the Intake valves had 0.510� of clearance and for the .500� lift of the cam that gave us 10 thousandths of clearance. I did not machine these, because I wanted to keep the stock valve seals. On the exhaust valves it was a different story. These only had about 0.480� of clearance. So I had to machine these. You can read more about the vortec heads at these websites:
Vortec Head 1
Vortec Head 2
(Both are for the v8 vortec head, but they are very similar to ours.)
I also had to machine for the Valve springs on both heads. The I/D of the springs was around 0.845�, and the O/D of the spring pocket was around 0.850� if I remember correctly.

Now you are probably worried about all of this machining, well you can do it in your garage, here are all of the part numbers for the tools, they fit in a drill with a half inch chuck, but they may be able to be ground a little to fit in a 3/8� chuck.
All from this web page
Comp catalog
Comp Stock valve guide specs
Arbor tool
4732-11/32� arbor
Valve guide cutter
4726- 0.530�
Valve seat cutter
4721-0.810�
Valve seals-
503-16
Get 16, because with all of the measuring and such you will probably break a few, they are kind of brittle

/see update^
Your stock rockers are actually very nice. I have the stockers. In 2000 they started putting roller trunions (centers) in.

If you want to go to an aftermarket one though, gm made it easy. Stock rockers are held in with a bolt and are non adjustable. For conversion studs you would need 8mmX1.25 bottoms, and whatever tops you want for the rockers, I have no experience with anything other than stock rockers on our trucks.
/see update^

I think the adjusting nut is a problem though with the stock valve covers. You could try some used stock steel valve covers out of an 80�s or early 90�s truck, but I don�t know if you could just get low profile nuts instead. Also don�t get more than a 1.52� ratio unless you are getting ported heads, because the stock flow on our heads maxes at around .500� of lift.

Installation
If you get the low lift (grinded cam), and you are willing to do some grinding on the springs you can get away with not pulling the heads. But if you machine the guides you are going to have to pull the heads, it isn�t too bad, there are a few grounds and such on the back of the heads, so I am warning you, and I had a hell of a time finding them all. The heads are almost identical; gm does this so to save on machining costs. So the bolts at the back are in the same location as all of the holes on the front of the heads.

The Haynes manual will tell you to take the upper plenum off of the intake manifold, this is an unnecessary step, all of the bolt holes (there are 8) are accessible with the upper plenum in place.

I would recommend setting the distributor to the lines on the harmonic balancer, and marking the distributor. This was my main hitch on both of the trucks I have done. This will also make it easier to get the bottom of the distributor mated with the drive for the oil pump.

Cleanliness with the valve train components is key. Make sure you drain the coolant before you pull the intake manifold. Other wise you stand the chance of getting coolant in your lifters, and I have heard of mysterious ticks from the lifters. You will also want to keep the lifters, rockers, and pushrods in their original locations when you put them back in, so get a box.

If you have any experience with the 350 Chevy, you know that the timing cover is a pain to remove and replace with the oil pan in place. It is a real pain to lower the oil pan on our trucks. Also the problem is amplified by the fact that it is plastic. My cover leaks, I don�t think I got it clean enough, and didn�t use enough RTV sealant with it. I didn�t drop the pan either.

It is possible to swap the cam without pulling the entire engine. It may be faster though. The radiator must be removed, and the A/C condenser in front of the radiator has to be un bolted, and rotated out of the way (don�t remove the lines). The A/C compressor can just be unbolted and then it can be rested on the bumper with a rag, with the hoses still attached. The power steering pump can stay attached to the bracket and hoses, and just moved out of the way where it is convenient.

Spray the hell out of the 6 manifold to Y-pipe bolts with some penetrating oil. This might make the nuts come off without breaking the studs. I broke 2 of mine on the driver�s side, and now it leaks exhaust due to my bad drilling and taping job with the studs. But now I have headers waiting to go it. I didn�t have to unbolt the passengers manifold from the ypipe, but it is easier to get to all of the bolts on the heads with it out of there. A lot of the lower bolts will be easier to get to from the wheel wells. The steering shaft has to be disconnected at the steering box. I would recommend marking it in relationship to the shaft it goes onto. The bolt just comes all the way out, and you can pry on it with a craftsman screw driver to help it telescope up.

Some people like to put all of the parts in bags, and mark every thing. I don�t do that because I have a good enough memory, but if you are doing this over a month or something, then it may be a good idea. All of the wiring has different connectors on them, so you can�t plug them into the wrong spot.

For parts, here are the part numbers that I went with you will also need the ones I mentioned above to machine the heads. You can get them from summit racing or jegs I am sure, and they are generally a little cheaper. The -12 at the end of the part number is the number of parts, if the place doesn�t have the part number try a -16 at the end, and it should work. If you go with one of the other cams, you might have to go with a different spring, and then you will have to go with a different seat cutter.
Taken from here
Comp catalog
Cam
Retainers- 751-12
Locks-611-12
Springs-983-12
Seals- 503-12

I have a cloyes timing chain; I can advance, retard, or install the cam straight up. It is a full roller, and is a nice unit; I just installed it straight up. I think the cams have 4* of advance ground into them from the factory. The factory chain will work, or you could also go with one from comp. Make sure it is for the balance shaft motor �92 and up. The p/n at summit is
CLO-9-3154

Most of the other stuff like gaskets you need is as follows, there may be other little things that I forgot
RTV sealant
Permatex #2 non hardening sealant
2 head gaskets
2 sets of head bolts
Lower intake manifold gasket
Exhaust manifold gasket
2 water pump gaskets
3 total gallons of coolant mix (depends if you get premix, or mix yourself, this is the total you should need though)
Oil
Oil filter (you will want to change your oil when you are done with every thing before you start it for the first time, and then change it in about 500 miles and check the magnet on the plug)
4 cans of brake cleaner (or compressed air for cleaning the heads after machining)

Special tools you will need
Torque wrench � 10ft/lbs-100ft/lbs
Harmonic balancer puller
(Be very careful of damaging the threads on the end of the crank, not that I have ever done this before or anything)
2 or 3 jaw puller for pulling the timing gear if you replace it
Assorted flex joints, and socket extensions
Torx bits