HI, just sharing for anyone looking to do what I did. Also looking for comments and discussion and sharing of knowledge in this area.

Coyles 9-1138 Timing chain kit for my 1996 E350 Club Wagon 351w. Leaking coolant from my timing chain cover. So I replaced the water pump as well and the gaskets for the cover behind it.
But noticed the oem timing chain with 115k miles had some stretch/slack. So I decided to replace with this superior affordable chain gear set. Why foolishly wait till the oem chain breaks when it gets somewhere over 200k miles?

***BESIDES, after research, this set's gear allows an optional advance key setting of 8 deg which advances the cam 4 deg. I live at 6k altitude.
I choose this optional setting and so far am happy I did. It sounds the same.
This change increased the cranking compression on the cylinder I tested before and after, by 28psi! and now the engine has more torque and perhaps better mpg. I pull a 3,200 lbs boat in the summer.
Making a right turn from a dead stop, flooring it, I can scratch/spin the rear tire some where before I could not.
I can't say about the gas mileage because my gas tank had a leak..

Now intake valve closes slightly sooner for the compression stroke to start sooner, more in line with pre emissions engines of the late 1960's. In the 70's and up, they retarded the timing for emission reasons. Many online suggest this change for all round improvement.
Many after market cams have this increase built in and one way they improve the engine performance.

Engine sounds and drives the same but has more torque when starting from a stop. The advance should also shift the peak power curve sooner (say like 400 rpm's) in the rpm's but I can't tell the difference. Still accelerates with power all the way through red lines up just fine when flooring the gas pedal.
I believe I'd still pass an emissions test if we still had one here.

Some more expensive like racing kits allow even more timing advance settings and some say to advance until the cranking compression peaks for best setting results. However that may not result in much more advance. I mean, I may be about to the sweet spot now. Also advancing more could cause engine knocking which would require retarding the timing or high octane gas. It would be interesting to play around with it more like that but I just wanted it simple.

Mark all your bolts for their positions, the bolt ends and their related holes! I used different colored paint pens from ebay. Take some pictures as you go as well, for reassembly. Take your time.

ANY bolts that are stuck, DON"T force them, they may BREAK. Instead, spray with wd-40 and let um soak. THEN move the bolt just slightly tighter then just loose, then repeat back and forth. This can break and fracture the crud and rust slowly away. Eventually you should be able to get more and more back and forth movement til patiently you can unscrew all the way.
Otherwise applying torch heat can unfreeze any corroded or rusted bolts.

You do have to reset our ignition timing anytime you replace the chain changes the setting since the old chain had slack.
Watch youtube videos and never hammer any of it, especially the cam shaft. Only use a rubber mallet instead at most and lots of wiggling and use pry tools as needed, to move tight gears and chain things into position.

Use black gasket maker rubbed on both sides of the new gaskets and some beads in the corners of the cover where it mates to the oil pan, for leak free sealing. Also assure the timing cover's crank shaft round seal is centered with the dampener shaft hub, slightly test installed to assure that round seal is even(timing cover position) and will not leak.

Any sharing what they know about this would be cool.