It's been done loads of times, just plastiguage it.
Other option to an insert, is cut it off and make up a bracket that bolts down with the cam caps bolts.
It just bolts up but whether it does anything is up for debate. Really the feed needs to be taken from the oil gallery under the ignition pick up... Or so the argument goes.
The block needs to be decked because the pistons sit above the deck, but that's with busa rods iirc.
Busa slugs will give low compression, dot head would bring it back up a bit but still on the low side.
@Duckndiveis the man to talk to.