edit ... i guess they are that deep , put then on ebay
my thought , get a flat top and build it as a quench motor either wit ha 6 pk piston .020 in the hole with a steel shim gasket or zeo decked wit ha .039 felpro, you have the heads to do it with and the engine will be less detonation prone , building it will a piston .100 in the hole it's going to be a pig .