It's listed on page 13 of the AMA specifications for 1971 Barracudas for 383's only 2444562, 12 Volt 56 Plates, 59 Amp-Hour.

slant six, 318, 340 is listed as 2875951, 12 Volt, 54 plate, 46 Amp-Hour

426 Hemi and 440 ^barrel are listed as 2642969 12 volt, 78 plate, 70 Amp hour