Dodge (Mopar) gave up on the Hemi late 1950s, (early 1960s ?). Mickey Thompson made aftermarket Hemi Heads for two famous specific engines, Dodge gave up on the Hemi, but after 1962 seeing some aftermarket MT Hemi Heads on the competition, got them rethinking, (1964 Mopar 426 Hemi). Most say this is what influenced Dodge bringing out the new 426 Hemi.
Mickey Thompson also made Hemi Heads for the 1964 Ford Fairlane 500 ''Thunderbolt 427s, Jess Tyree ex Pontiac Racer used them on his 1964 Ford Thunderbolt!

l think one of them was the old 354 and the other was the 392 hemi,s, l could be wrong on this one,its been a while since l have seen one of either of those,good luck.

In 1951 Chrysler introduced it is first V-8 engine a 331 cu. in. Hemi producting 180 HP at 4400 RPM., By 54 it upped HP to 235.
1957 Chrysler & Dodge both used Hemi or more precisely polyspherecal heads on there 270 cu. in., Red Ram, & the 315 cu. in. Super Red Ram, also called the D-500, & D-501 option, they made respectable power for the day, topping 260 HP at 4400 RPM. (D-501)
In 1957 they offered a 392 Hemi (optional 300C) rated at 390 at 5400 RPM. 1958 was the last year for the ''Red Ram '' series Dodge offered the D-501 option 354 Hemi rated at 340 HP.
1964 dodge offered a Nascar 426 Hemi V8 option 400HP
a Hemi Charger V-8 option rated 415 HP & a Hemi Charger eight barrel V-8 option rated at 425 HP
In 65 only two Hemi is were offered 426 Hemi V-8 rated at 415 HP & 426 hemi eight barrel rated at 425.
by 66 the Hemi was offered only two ways hydraulic or solid lifter design both factory rated 425HP. this continued thru 1971.
It is likely that Chrysler saw the potential in the Hemi design, but really only utilized it for there racing program, it was too expensive to re-tool the plants to produce all there engines with the polyspherecal design, & later racing experience would make light of this fact as the Wedge Head engines raced well also.
Check this site for the complete story
http://allpar.com/mopar/hemi/chrysler-hemi.html