Aside from the spider, not really. The new spider performs really well, no extended cranking, no rough idle, rpms drop smoothly with no hesitation. The tune up parts had no noticeable effect on the feel, but it was time to change them out at 90k miles.

 

I hope all these parts correct my problems. Every so often it just falls all over itself and then doesn't do it again for sometimes weeks. I just put a new radiator, mount grommets, upper and lower hoses, water pump and remote oil hoses along with the cooling hoses.
Mine has always seemed a little doggy but I didn't buy it to race...
Later

 

You will only see a difference if you had a problem with one or more of the old parts.


Put a new Delco cap/rotor on, install new Delco platinum spark plugs, and set cam retard to exactly zero when the distributor goes back in. That will most likely get you some performance improvement if all other things are OK. Ignition systems are critical to performance in these Blazers.

 

Technically, you're correct. Here's the factory info I have:
The bolts are almost always too corroded to reuse, IMO. If you use new, genuine Chevrolet bolts, part # 12550027, those bolts are coated with sealant/thread lock by Chevrolet. Most of the aftermarket "bolt kits" also have factory-coated bolts.

I've done a bunch of intake manifold jobs on GM, Chrysler/Dodge and Ford truck V-8 engines (as well as a lot of Mercedes Benz and BMW V-8's and Volvo, Audi and VW inline and VR series engines), and I've always used anti-seize on intake bolts for the reasons I esplained above. I've never had a problem with leaky gaskets caused by bolts working loose.

When I do my lower manifold gaskets later this week or next week, I'll use anti-seize on new stainless steel bolts. I want the job done right, to last a long time. I'm not worried about voiding the warranty on my 1996 model with almost 180,000 miles on it.

The cleaner you get the heads and manifold surfaces, the less likely you'll have problems.

Let me see if I can save a couple of images and upload them here.

Make sure you figure out which side is up on the gaskets. They should be marked. The factory calls for a small "patch" of sealant on the cylinder head side of the gasket, at the wide spot on the end of the rubber going down to the front and back block web sections. Here's a pic (I hope):



That patch has two purposes. First, to hold the gasket in place as you assemble things, and also to put a small bit of sealant under the gasket where the head, block and manifold all meet in the corners.

Then, you place the gaskets on the heads. There are dowels in the gaskets to locate them properly on the heads.

Then apply a 3/16" (5mm) bead of sealant across the front and back webs on the block. Don't overdo it. "The bigger the blob, the better the job," does not apply in this situation. Extend those beads up onto the gaskets 1/2" at each end. It looks like this:



Install the manifold and bolts and tighten the bolts in this sequence:



Tighten the bolts in sequence to 26 inch pounds (some versions of the factory manuals say 27 inch pounds, but I doubt 1 inch pound difference matters).
Then tighten the bolts in sequence to 106 inch pounds.
Then tighten the bolts in sequence to 132 inch pounds (11 foot pounds).

This is a job for the 1/4 drive "inch pound" torque wrench.

BTW, this is the exact same procedure as for the Vortec V-8 engines, mostly because it's the same engine with two cylinders removed out of the middle.

 

Thank you for the info. Very nice write up!
I was looking at the cap and rotor yesterday and yes, it needs to be replaced.
It's actually not that old. it was replaced right before I bought this ride a short while back. It's not ac brand though and it has green corrosion on the contacts.
Later

 

Sorry to resurrect a 5-year old thread, but I've been searching for information on replacing the lower intake manifold gaskets. Hopefully this isn't a dumb question, but don't want to get started on the wrong foot: Should I drain all coolant before starting this job? I need to change the coolant anyways, but would prefer to do it afterwards. Fix one thing at a time, keep it simple (if "simple" applies to this job in any way).

Any input is appreciated. I'm off to find a power steering pulley puller.

 

Yes, you will neef to drain it some but not completly. For one thing the heater core is higher than the thermostat.

There several good write-ups on the whole process. Have you found them? Look for the ones with the attached files with details along with the part number for the preferred gasket set.

 

I've searched quite a bit but a lot of the threads reference outside articles that are now defunct (handymanlyness.com). Otherwise I've used the search function to my best abilities but haven't found a comprehensive write-up. There is one good one with some tips like having a pulley puller available, which somehow all the videos I've found just leave out. I guess they assume everyone knows how to do that. I'm confident I know the overall steps/procedure, but some of the details like the coolant are lacking. Any links are appreciated, if still active. I plan on using the full monty Fel-Pro gaskets (metal backer), replacing the manifold bolts rather than reusing, and having my blue loc-tite and in-lb torque wrench at-the-ready. My Blazer is a 1999, but it only has 128k on the odometer, so I'd like to get quite a few more miles out of the old girl.

Steps (as I understand):
1. Disconnect battery
2. Drain some of the coolant. I expect this allows easier removal of heater core lines and drainage from this upper intake volume.
3. Remove air intake, filter box, MAF assembly.
4. Remove throttle body, associated connectors. Move throttle body assembly over to driver-side of engine compartment with cables still attached.
5. Disconnect loom connectors, as many as you can find. Then find some more. Digital photos are your friend for re-assembly.
6. Disconnect plug wires from distributor, remove distributor cap, then remove distributor (carefully mark before/after you extract)
7. Disconnect fuel lines beside distributor using a 16mm or 5/8" crow-foot flare nut wrench.
8. Remove serpentine belt, disconnect and set aside AC compressor.
9. Optional: Disconnect and remove alternator for better access to passenger side manifold bolts.
9. Remove Power Steering Pulley (tons of fun). Removing fan from water pump may help access, or at lease remove fan shroud for better access. Fan removal can be a PITA.
10. Remove bolts and nuts to aluminum casting that supports AC compressor to allow access to front intake manifold bolts.
11. Remove 8 manifold bolts, carefully remove. It helps to zip-tie the wiring loom up and out of the way as much as possible.
12. Clean surfaces, replace w/new gaskets, and reverse process for reassembly.

If you've made it this far, thank you. If my process changes, I'll report back and edit as necessary. Cheers and happy hunting.

 

You don't have to take off the P/S pulley or the engine fan/water pump. Plenty of instructions on this site - look harder.

Don't use power tools and scratchy pads or any kind of abrasive to remove old gaskets no matter how wonderful the writeup seems. Razor blade or sharpened putty knife only. You don't want the residue circulating in the oil.

 

I'm back at my computer. Here are some of the write-ups that I have kept as pdf files. I followed the Handymanlyness instructions.

Advice/lessons-learned from when I did my LIM gaskets:

• I had a hell of a time finding a nut that secured the bottom of the PS pump bracket so I could ease it forward a bit. If I had read the instructions more closely, I could have saved about 45 minutes! Lesson: When it doubt, read the directions! LOL
• I also got new replacement LIM bolts.
• I wish I had cut the heads off of two of the old LIM bolts and loosely installed them to act as guides for placing the LIM inplace.
• I wish I had purchased new RTV for the front and rear block rails. I think I have a small oil leak either because the RTV in the gasket kit was old or I did not use enough.
• I was glad I got the whole gasket set from Felpro that has the lower and upper intake gaskets and o-rings. This is the kit with the metal carrier for the LIM gaskets. pn MS 98002 T. This also has the valve cover gaskets.
• This is a good time to check all of your vacuum hoses. I had to replace the angled one that goes to the PCV valve.
• I was glad I was careful with laying shop rags in the lifter valley and blocked off the intake ports.
• I had the money so I also upgraded the fuel injection spider with a new unit. (see my build thread)
• If you have an exhaust gas return tube, use two wrenches to undo it. Another forum member learned that lesson the hard way.

Good Luck and don't hesitate to ask questions.