The 340 is the biggest POS V8 Chrysler ever made.

I just have to say most of this (racing/performance) stuff is pretty esoteric.
Over years I've had more than one mechanic express an appreciation for the reliability of a LA.
One wanted to buy my car and neither were brand loyal.
I want to get from Point A to Point B.
Not just go a quarter mile.
So, is there a fundamental difference in engine design between LA engines that would make any a "POS"?
I can't speak to the off the shelf comparable GM engine since I've never had one.

Have had a few Chevys and have friends who run them and just like anything else in this world there is better and worse,i can appreciate both styles,for comparison,the smallblock mopar has shaftmount rockers wich is great,but we are also stuck with a lifterangle and location that is beyond full retard compared to a SBC,Sure we have ½" headbolts,but we are stuck with just 4 bolts per cylinder where a SBC has 5,Smallblock mopars has a nice cast aluminum front cover a SBC has a pressed steelcover. Plenty of SBCs with 4 bolt mains,but hey the smallblock mopars has a higher deckheight. Chevys have HEI ignition with everything inside the distibutor,Mopars has much higher camlocation in the block making strokers much easier to build. Moparsmallblocks has a very nice sparkplugglocation and angle for acces on cars with headers,SBC has a much wider boltpatern on the exhuast side of its heads.

Listing god and bad sides can go on forewer,what it all boils down to is what body style we prefer to wrap that engine in and its usualy easier to put a mopar engine in a mopar and a chevy in a chevy.