Today? 65 Barracuda ENGINE # knowledge needed!

on the side of the engine, {if I recall correct;drivers side} hidden by the exhaust manifold is casting numbers.

http://www.yearone.com/updatedsinglepages/id_info/mopar/mopar casting numbers/castingnumbers.html

CASTING # C.I.D. YEAR GROUP
2465330 273 1964-66 LA
2536130 273 1965 LA
2466090 318 LA
2536030-318 318 1967-75 LA
2566080 318 LA
2806030 318 1967-74 LA
2780930-340 340 1968-73 LA
3577130TA-340 340 1970-71 LA (Trans Am)
3418496-360 360 1971-74 LA
3870230 360 1975-UP LA
2264230 318 1960-66 A
2468230 318 A
2532630-318 318 A