So, I have a 98 Blazer 4X4, 4-door, 4.3Ltr Vortec. I'm starting to notice the "crust" forming at the intake seam next to the valve covers indicating a coolant leak. I haven't had to add any coolant yet but it can only get worse so, before Fall, I'm going to replace the intake, and up, gaskets.

Now for the questions.

1. I have the P0404 EGR code. While I'm in there is it worth it just to replace the EGR? It's $80 and I won't have to deal with cleaning it now & then, the code reoccurring in 6 months or spending hours soaking & cleaning to find it didn't solve the problem.

2. What is the best intake gasket kit to buy? I own a Pontiac GA & replaced the gaskets several times to find out that the gaskets I was buying were not high enough quality to resolve this, very common, issue. Bought the good ones & haven't had a problem in 4 years vs the every 6 months replacement.

3. While I'm replacing the gaskets, is there anything I should be on the lookout for? Anything I should replace or test while I have it apart?

4. While I'm replacing the gaskets, are there any upgrades I can do to increase performance, or MPG? Such as, swapping an intake, TB or other parts from another vehicle, rebuild a part, replacing a sensor with a better one or removing or modifying parts.

I'll be doing the gaskets in about a month, unless it starts gushing like a fountain beforehand, so any suggestions, ideas or comments are greatly welcomed. I'm not looking for 50HP or throwing $3k on a turbo/SC kit or anything like that. I'm just looking for a bit of tinkering or resolving problems that are known or will pop up. Spending $100-200 on a part here or there isn't a problem. Just want to have a little fun messing around a bit. Thanks in advance.

 

the throttle body is actually already overkill for a 4.3, no upgrade nessesary. There isnt much aftermarket support for the 4.3 vortec intake set-up without changing it entirely.

Look for evidence of fuel leaking (lean spots) under the upper intake

You could do the mpfi fuel injector swap, not very hard just costs $200+ in parts

Fel-pro seem to have intake gaskets that are better than the factory crap ones

New EGR with a screened gasket

 

I'm surprised the TB is overkill. Usually it's the other way around.

I'll definitely keep an eye out.

I Goggeled the injector swap. Didn't know that was a thing..lol I will be doing that for sure. Besides keeping the injectors from clogging does it effect performance or is it just a futureproof?

I've always used Fel-Pro gaskets when doing the V8 vortec intakes, just wanted to make sure they were adequate for the V6 version.

That's what I figured. Just replace the POS & be done with it. EVERY GM vehicle I've owned has had issues with the EGR eventually.

Any ideas on air intake? Removal or modification of the air box. CAI?

Before winter I'm upgrading to the 140/145A alternator & installing a new battery. I installed a new stereo system & built & installed micro PC for music storage and the charging system is starting to show its age.

 

The mpfi is only an upgrade if your current injectors are leaking or clogged. If they are you will see a major improvement. If they aren't you wont notice. I dont have the part number, but the gaskets you want are the fel pro that is made of rubber and metal.
You can do the throttle blade mod while you are in there, doesn't add horsepower but makes the accelerator more snappy.

 

What's the throttle blade modification, and can it be done on a TBI?

 

I used Fel Pro intake gaskets when I did my gaskets. Their plastic ones are plenty sturdy, but they make awesome metal gaskets too. The choice is yours!

I wouldn't wait to long to replace them. I blew a motor from coolant leaking internally into the engine via leaky intake gaskets.

Honestly the best things to do if you want to "tinker" is, upgraded injectors, deep clean everything, new sensors on upper intake, new distributor rotor and cap since you'll have to take that out anyway. If your really ambitious you can get a marine intake and drop that in. But thats pretty spendy. You can also bore out the throttle body, and or chop off the throttle plate restrictor.