Does it still try to “rev high”? Good chance of an air leak, leopars have been known to spit out the crank seals on either side from time to time. They can’t be seen without removing the ignition rotor and/or clutch. An air leak would also cause what is going on.
Rapid Racing Inc.
Vintage B-Stock Pilot
"When in doubt Gas it, It won't help but it ends the suspense."