I HAVE A 427 /942 4 BOLT THAT SOMETIME IN IT'S LIFE HAD THE BLOCK SURFACE O RINGED. I AM LOOKING FOR ANY AND ALL INFO ABOUT AN O RINGED BLOCK. WHAT I WOULD ALSO LIKE TO KNOW IS IF THE STAINLESS WIRE THAT IS INSERTED IN THE BLOCK CAN BE REMOVED AND A STOCK HEAD GASKET USED. IS THIS A WORKABLE TYPE FIX OR IS THERE SOMETHING ELSE THAT CAN BE DONE.I HAVE NEVER HAD AN O RINGED BLOCK.PLEASE GIVE ME YOUR THOUGHTS.I AM JUST LOOKING TO PUT IT BACK TO AS CLOSE TO STOCK AS POSSIBLE. I HEARD THAT ONE OF THE PROBLEMS WITH O RING AND COPPER HEAD GASKETS IS THAT THEY WEEP COOLANT ECT.
THANKS,
WES

 

This answer comes to you very slow, I have never visited this part of our forum before today.
O'Ring blocks are for extreme high horsepower engines. On your big block I would guess that number is above 700 HP. As you make more power the pressure in the cylinder keeps going up, a normal 350 in stock form at wide open throttle might make 600 PSI and runs perfectly for life with no gasket failure normally.

A performance built 350 with 12:1 and all the tricks to make double the stock horsepower might make 900 PSI in the cylinder and a performance gasket would be needed.

Now step up higher and start making 1000 HP with the same engine and the pressure goes up till the head actually is lifting off the block when it fires, this happens when the bolt clamping force can't keep the head down on the block. The head starts bouncing in normal operation with this engine. Maybe it has turbo's or a blower to build this kind of cylinder pressure. Racers determined years ago they could seal this engine with a wire oring around the cylinder. They milled a receiver groove in the head and block, then installed a wire into the groove and bolted it up. When the head bounces the wire maintains the seal even though the head might be lifting 1 to 3 thousands of an inch with each combustion stroke. Today Top Fuel and Top alchohol engines still use the wire ring but up to 1,500 HP engines run MLS gaskets which allow for more head lift without losing seal.
As long as the fire ring of the gasket does not sit directly on the wire ring you could run normal gaskets right over the Oring groove. If the fire ring sits on the wire groove you would be risking compression leaks.
On the Oring Blocks and heads Racers had determined they had to run this system or face failure due to combustion seal loss when the heads jump up and down.
They lived with coolant leaks as a compromise to maintain combustion seal.
Not good for the street but OK and normal in racing, Drag racing mostly.

 

I have o-ringed heads on my supercharged engine. Felpro now makes special head gaskets for O ringed blocks and heads and uses no wire.
My gaskets are $142.00......EACH but work great.