Wally,
yes. It is a 305.
Both the intake gasket and the coolant hose connector were eaten away.
the coolant hose connector was intact on the exterior surface and
completely deteriorated from the inside out.
The intake gasket also looked to be deteriorated/chemically reacted around the water passages, but I have no experience with those plastic gaskets. (The torque spec was ridiculously low so not to crack the plastic but just compress the rubber o-ring within them.)

So, thank you for pointing out that my problems may not have been related to the anti-freeze.

Actually GM makes a product called 'Top Engine Cleaner' which does a great job. Will even decarb stuck rings. I had a Chrysler service rep buy some to fix a Jeep with carbon knock after I proved to him it worked. I'm still not sure how he got that claim past the auditors.

There is two different coolants w/ two different colors

the GREEN kind is a Propylene Glycol. This has silicates, phosphates, borates, nitrite, and amine additives that keep you radiators very clean. This is why the animals die when they drink it.. Anyway, the upside is it keeps everything clean. The downside is that some of the additives are bad on your pumps and seals, and does not have as high of heat transfer as the RED STUFF..

The RED STUFF is Ethylene Glycol. This stuff is eviromental safe because the additive that it has are organic. The additives form a caboxylate which creates a better heat transfer. The mixture should be at a 50/50 mix. When it is diluted this is when it causes inhibitor to cause pitting and corrosion

Believe it or not 100% Sufuric Acid will not eat through metal. Dilute it to 5 or 10%, you better watch out. It eats right through.

Anyway if you mix this with the green stuff then your suppose to change it out like every 2 years i think.

Pros -- enviromentally frendly, better heat transfer rate, no additves that destroy water pumps and seals, (if added with proper ratio), and longer change intervals( (this is because it has no silicates)..

Cons- an exact science and must be mixeed at the proper ratio, can release corrosion inhibitors if not mixed prpoerly,


Personally, I like the Dexcool but I am a maintenance freak also. I change all of my fluids(all fluids) every 30K miles and have never had a prob. I just never thought it was expensive to change them at 30k miles. Besides if most of us treated our vehicles like we treated our boats they would last a lot longer too..

I know of TEC and have used it in the past.......rumor has it though that you wont be able to get it over the counter anymore....only avail to Techs etc.....that would suck if its the case..

Has anyone had experiance with the sea foam then broke an engine apart??

Just wondering how the carbon build up looked after using it??

Merc makes a cleaner for ouboards that works fine in Chevy's. PowerTune is the can name?