stubborn exhaust manifold gaskets Options

[87m491]

Finally swapping in SS heater boxes I acquired years ago and I can't budge the existing manifold gaskets. I have read and tried a few options, trying to leverage a pick under and edge and walk it out, no luck., the gasket is very tight against the engine. Trying to lever a screwdriver head against and gasket edge and the head to deform the gasket a touch except that my head's fin started to deform before the gasket! Any other tricks before I give up and just try reusing the gaskets that won't seem to come out?
Thx
(IMG:http://www.914world.com/bbs2/uploads_offsite/i.imgur.com-14731-1708433712.1.jpg)

[technicalninja]

I did mine in our 75 upside down.

They were stuck like a bitch too.

I used the cheapy harbor freight pick to clear around the perimeter of the copper ring and the parting line at the head exit FIRST.

Got all the carbon cleaned off and hit it with PB blaster. Let it sit over night.

Still stuck pretty well and I just worked the pick under the oval until they finally popped free.

You're still super dirty around the ring...

[87m491]

I did mine in our 75 upside down.

They were stuck like a bitch too.

I used the cheapy harbor freight pick to clear around the perimeter of the copper ring and the parting line at the head exit FIRST.

Got all the carbon cleaned off and hit it with PB blaster. Let it sit over night.

Still stuck pretty well and I just worked the pick under the oval until they finally popped free.

You're still super dirty around the ring...

Because I like closure on threads, and public ridicule, here's the rest of of the story. Given the precise fit, decades old, and hundreds of heat cycled nature of the gasket's history, there was NO WAY any pick was getting in between the gasket and the cylinder head period. I turned a nice flat bladed screw drivers tip 90 degrees and ground a nice sharp edge on it and it got me no where trying to lever around the gasket. Not heat, not penetrant nor cold chisel budged it at all.

I then went with a previously broken wood chisel (~3/16s wide) and put a nice point on it.
(IMG:http://www.914world.com/bbs2/uploads_offsite/i.imgur.com-14731-1709558684.1.jpg)

While the chisel dug through the gasket, one mis strike also left a nice gouge on an engine fin and still didn't immediately provide an opening to lever out the gasket!
(IMG:http://www.914world.com/bbs2/uploads_offsite/i.imgur.com-14731-1709558685.2.jpg)

One might think such a deep cleave in the gasket would easily accept another screw driver blade surfaces to work against but that fit was tight!

(IMG:http://www.914world.com/bbs2/uploads_offsite/i.imgur.com-14731-1709558685.3.jpg)

Success was finally achieved but the remaining 3 will await an engine drop and then oil return tube removal so as to proved a few more degrees of leverage which hopefully will make it less of a PITA next winter.
Interestingly I "sound checked" the gasket on removal. While a new one tinkled nicely as the hit the floor. The replacement which I annealed before installing made virtually no sound when dropped on concrete and the removed unit was definitely somewhere in the middle, i.e., maybe is was not annealed and that added to its stubborn removal?


Thanks for the suggestions.
(IMG:http://www.914world.com/bbs2/uploads_offsite/i.imgur.com-14731-1709558685.4.jpg)