Point is, the 360 had it's own casting, regardless of where it originated from. The theory that Chrysler didn't want to make a "special" head for the 360 is false, they did.

When I say 360 I am talking LA, the 5.9 would be the Magnum variety.

theyre still all "318's" and "360s" to me I despise the metric-if-i-cation of everything.....
some interesting points being brought up here.....

Yeah I did buy them "already assembled". The previous 2 sets of EQs id bought, Id gotten as bare castings and assembled myself. thats the first and last time I buy "fully assembled, ready to run" EQs.
I dont know, about the possibility of them standing behind them/// I parked it because I was so beside myself as it definitely wasn't my first engine build, wasn't my first time running EQ heads, but was my first engine overhaul that went south. I left it sit as my garage ornament/ and we got by on our other vehicles, at one point i almost hauled it over the scale I was so mad. kind of put it on "time out" so to speak. I did everything on this durango thinking we were gonna have it forever.
The rebuilt engine was one I bought off of CL/ and got conflicting stories about its history when I went after it/ so it gave me doubts, so I was kind of afraid of running it "as was"/ so I wanted to make sure all was good with it, before I stabbed it in. it was just a run of the mill used takeout at that time before I pulled it apart.
I also still have the original engine out of it sitting here, as well, pulled with 258,470 mi. the bottom end was starting to get a little "rattley".
 I rebuilt the trans, since I had no history on it and it was "out".
Id been having cat efficiency codes, so it got a brand new cat with the rebuild and new O2 sensors. Because that cat melted down when the rebuild tanked, the current engine in there, got another new cat with the install. Magnaflow "HM series" both times.
I replaced the fuel pump just because.
I rebuilt the front suspension, poly bushings throughout.
I put brand new HD/towing rated leaf springs on it
I sent the injectors in to be rebuilt.
same with the starter and alternator, to the local starter shop.
after it set almost 3 years I happened across another 360 on CL that seemed almost too good to be true and I jumped on it. We're still driving it with that short block and that bad set of EQs that started the mess with the rebuilt engine, on it after paying a machine shop to fix them. I was pissed to have spent money on brand new heads then having to pay again to have them gone thru to make them usable.
The durango sat in the garage for 2-1/2 years as a garage ornament because I was so pissed at it.... the warranty on those heads was 1 yr if I remember right. it wasnt til I bought that 2nd CL engine, and I decided to run it as was (except for new gaskets and freeze plugs) and I took those heads in to be checked when I had them off for new head gaskets, I found out they were cracked, so I pulled the EQs off the rebuilt figuring I could just stab them on this other engine, and I discovered the stuck and bent valves.... I also robbed the new double roller timing chain from the rebuilt engine, its currently on the engine that's now in there.
were still driving that durango, the body just turned 312k miles, its body is still better than many vehicles 10 years newer around here..... the short block in there has about 135k less miles than the body.
other than the EQ heads the only other mod on the engine that's now in there is a set of 1.7 roller rockers I got off a buddy of mine.


I didnt get the 2nd durango I was thinking of building this engine for, the "R/T" turned out to be an SXT witha rotted body out back with a 4.7 in it..... all it cost me was a few hours of windshield time and rental of the tow dolly which I wound up not needing.... were still looking.

I still want to make that doomed rebuild right.... I guarantee I will find something to put it in. so I want to re rebuild it regardless. so Im still gonna scope out this buildup I have in my mind.... maybe I will run across a deal I cant pass up on a set of aluminum heads for it. It seems that eventually things find me "if" and "when" I'm not in a hurry for them. If Im in a hurry cuz I neeed something "now," I wind up gettin screwed.

In the post above perhaps I need to clarify that the point I hoped to get across was:

In the years of the Magnum V8s Chrysler was trying to save money by having just one cylinder head for the 5.2/5.9 and one piston for the 5.9/8L V10.

It is worth pondering that the 5.2 had a flat top piston crown, the 5.9 had a soapdish and much later the 5.7 went back to a round cavity with an annular quench clearance surface.

When considering these it is probably just as significant to take into consideration the quench clearances of each combination and robustness of the squish.

Later the Viper V10 got lots of changes in combustion chamber details either from Chrysler or speed shops.

Customers complained about “pinging” from build up of carbon deposits on the piston on 5.9, somewhat less on 5.2 and less on iron V10
The “Death Flash” was Chrysler’s “gift” to its customers asking for help.

“Maximum Bob” Lutz has said that Chrysler had bought a “Computer Engine Design Program” and he ordered V10 built to “educate the engineers” about how to use this new computer program and find out all the “whiz bang” it could show to us slow error prone humans about engines. Skynet, kinda.

This post gave me a new question:
the computer program outputted stuff about combustion in the V10.
Bob Lutz also ordered his engineers to write a technical paper about the iron V10 for the Society of Automotive Engineers.

If the time had been taken by the engineers to input all the details of the older 5.2 and 5.9 combustion chambers into the new computer program, what “Tweaks” would have been suggested?

In 1998 the 5.9V8 got a few changes,
at least a new camshaft grind and exhaust system components, probably new cat con and Software changes in PCM.
EGR valve deleted maybe that year or year before.

Did the computer program bought new in 1992 that first analyzed the V10
finally get data and analyze deeply the 5.2/5.9 V8s?

The iron V10 cylinder heads are not debated as much.
Do V10s have the cylinder head cracks too?
Were iron V10 heads
cast/hardened/tempered/machined
by different supplier companies than 5.2/5.9 heads?