Cracking half a dozen heads on 2 different blocks..
Warped blocks.. (cylinders were out of round and not parallel with one another, also had several obvious hot spots)
Uneven cam journal wear (cam bearing holes in block were all out of line with each other) that a machinist has never seen in another engine..
One block cracked around a head bolt.
A brand new Jasper rebuilt longblock that didn't last any longer than the previous engines.
One wrist pin walked on me due to a cracked piston pin bore.
More heads and torque to yield bolts replaced than I can count. Even ARP hardware was tried..
Several radiators and water pumps replaced trying to cure the head cracking problems..
A couple oil pumps replaced while we already had the engine out.
Tanker loads of coolant wasted.
The list goes on..
Ford built a shit engine that cracked tens of thousands of heads. This much is known. Bad head design. Bad enough that an aftermarket manufacturer stepped up to build a new head casting, which should have been Ford's doing...
Bad block design also. The 2.9 was packaged too tightly in my machinists opinion. It was cast too thin in many locations according to him.
This is all I can remember right now. I'm sure I've forgotten a lot of it over the many years since I owned a 2.9