Felpro makes the metal framed gaskets as well.

A cracked block is possible, but unlikely... really sounds like an intake manifold gasket problem. Seems like you are loosing coolant way too fast for a simple crack to a water jacket.

 

Thanks, Kyle. Back to taking the intake manifold apart...

 

Here's a good one for you!
To recap my latest issue...after changing head gaskets and putting the engine back together on my 1996 4.3L 4WD, I was losing about 3 inches of water from the radiator (without the engine running) and it was ending up in the oil pan. Pretty much considered the problem to be intake manifold gasket installation error (gaps in RTV maybe), so I was going to change the gasket and try again.
Instead of "wasting" another intake manifold gasket for what might not be the problem, I RTV'd some gasket material over the water jacket holes with the intake manifold off.After refilling the radiator, I still lostwater to the oil pan(had the oil pan drain plug off so I could easily tell when the water flowed).
While I was pouring water into the radiator, I happened to see water flowing out of a smallhole (approx 1/4")near the top of the distributor tube. Is just below and to the passenger side of the balance shaft, but inside the hole where the distributor shaft goes.
Now my question...
How is water coming out of this hole?
Anyone know why oil comes out of that hole? Is there a rear bearing for the balanceshaft that is being lubricated?
Is there awater jacket passage on the rear of the block that might be cracked?
Would appreciate any thoughts/ideas.
Thanks,
Steve
1996 4.3L 4WD

 

To go along with my previous post...
I've been looking all over the internet fora diagram that shows the rear of the engine block for a 4.3L. Wanting to try to trace oil gallery and/or water jacket on the rear of the block. Any suggestions for where I can find this information?
Thanks.
Steve
1996 4.3L 4WD

 

Just an update...
I spoke with a very helpful mechanic at my local Chevy dealership, and we deduced that the hole where I have water coming fromat the rear of the block (inside the distributor shaft hole) is the oil outlet for the rear camshaft bearing. Best he can figure is an internal crack that is allowing one of the water jackets to leak into one of the oil galleries.
Pretty much determined that I just need to pull the engine and have the block checked out. Any last minute ideas that might allow me to not pull the engine?
Thanks,
Steve
1996 4.3L 4WD

 

You could remove the intake and water pump, fashion up some block off plates to block the water pump holes and the coolant passages in the heads, then pressurize the system and look/listen for leaks. If the leak were to be caused by a crack in the block, you should be able to locate it fairly quickly.

Have you checked compression after you replaced the head gaskets? Is it possible that there was a problem with the head gasket installation (torque, flatness, etc)?

A leak into the lifter valley (what I assume you are talking about when you say under the distributor) could be caused by an intake manifold gasket failure which I guess you would have fixed in your attempts already. The intake gaskets used on this motor are not meant to have any RTV on any of the sealing surfaces besides the front and back rails of the block. RTV on the overmolded intake gasket will cause it to fail more quickly.

If you do not want to remove the motor, then you have to try other means of eliminating the possibilities.