Well unfortunately I am no where close but I would suggest if you do not have one to purchase a Factory Service Manual. There is no more important tool you can have. It will give you the confidence if you have the determination.
I did this for the first time about a year ago and it isnt that hard. I guess the hardest thing was getting the runner bolts out cuz they are in bad spots but a universal swivel and multiple length extensions help a lot. There are also a couple of bolts (1 each side) that are on the inner site under the plenum. Keep all the bolts in a sandwich bag marked as to what they are. There are a couple different lengths so I marked each with tape denoting correct position. Unplug or remove anything extraneous holding the intake down and mark each with tape as to what and where. After you have the plenum and runners off, remove the intake bolts then the intake. You may have to smack the intake a few times with a rubber mallet to get it to separate.. Stuff any openings with rags and scrape all the old gasket material off the intake and the heads being careful not to gouge the metal.
Re-installation requires three things. The gasket set preferably from Felpro, RTV silicone gasket maker and something called gasket tack. Permatex makes some, its called.....wait for it.....gasket tack and sealer. This holds your intake gaskets in place while you set the intake back in place and seals the water passages. Follow the tack's directions and you wont have problems.
Start out by using gasket tack to set the intake gaskets in the correct position. Then put a generous 3/8 bead of RTV on the china walls front and back all along the edge and up the head just a tiny bit to meet the new intake gaskets. Carefully set the intake back down as close as you can get it without having to move the intake around to line up the bolt holes. The 3/8 beads of RTV should bulge out a little bit. Dont worry about what it looks like if its messy as long as it seals the front and back china walls because its actually easier to trim it off after it dries. Reinstall the intake bolts putting a small amount of RTV on the first couple of threads to seal them up. Be careful of any bolts that dont go all the way thru the head. These dont require sealant and using too much RTV may cause the threads to strip out because of air trapped in the bolt hole. You can check for these by poking the holes with a small screwdriver. All other bolts must be sealed or you will have oil/water leakage. Follow the Factory tightening sequence and torque specs.
With the intake back in place, you can reinstall all the misc. things you removed. Reinstall the gaskets and your runners on both sides and tighten them according to spec. These do not require RTV or Tack. Remember the bolts thread in to the intake and plenum where the bolt fits flush with the runner flange which is not parallel to the plenum in some spots so they kinda angle in. Use the flange as a reference. Unless it threads in finger tight, reverse it out and try again. Dont strip out the threads!
Ease the plenum down on the runners with the gaskets in place. You may need the rubber mallet again to tap it back in place. Dont force it but you can be firm. Loosening the bolts at the intake base will help but you still have to re-tighten them and access is difficult so choose carefully. Tighten everything to Factory spec.
Double check everything, especially vacuum lines, they are easy to miss. If everything looks good and the RTV has had time to set, fire that bad boy up!
Hopefully This will make you feel confident enough to tackle this on your own. Its tedious but not hard. There are a few things to watch for but I think I have noted all of them for you. Like I said mark everything, put the bolts and whatever in separate bags with notes written in permanent marker. Take plenty of pictures of everything.
I have done so many "firsts" on my C4 and have learned so much about electrical and mechanical systems that there isnt much I am not scared to tackle mosyt everything. I do recognize where I may not have the tools or skill set to do a few things but I will not hesitate to give anything else a go. My '85 is my DD so it HAS to be running and I am broke so I HAVE to be the mechanic.
Good luck!
