Magnum, Magnum R/Ts

Yes, the factory magnum heads are hit and miss when it comes to good cores.
I have a pair on the porch right now [all cracked between the valves.
The push rod pinch is too tight on these heads and with no ability to sleeve the push rod tubes and open it up.
[instead of drilled holes you can press sleeves into and roll flat] there open on the side. So when assembling make sure that before you put your ford style rockers on that the push rods don't fall over into the valley.[joke]

The RT's make up for all of that, well almost, But none the less the flow is awesome right out of the box pretty nice multi angled valve job into the chamber. Main thing is they don't max out @250cfm like ported stock mag's and don't crack!
New mancini had them for $750 a pair.
Used ? like LX said good luck with the potential of these heads I don't see anyone taking'em off to sell.
Only one problem...
If you want to go 2.02 with these heads and guides prepare to spend $18 a valve,$140 retainers,$29 keepers. QUOTED mancini.only mopar makes them.
So easy fix enlarge guides for long stem 11/32 or what ever stem and valve size you want.
I think that everyone should give these #'s a look as a rough base line of what's what.
http://users.erols.com/srweiss/tablehdc.htm#Chrysler