Found this chart on My Mopar. Looks like only year for the A-318 (poly) silver was 1960.
Mopar Engine Paint Color Guide 1960-1974
Engine Paint Color Guide
Engine Years Variations Color Mopar Part Number
170 Six 1960 non Valiant Turquoise P4120752
170 Six 1960- 69 Valiant Red P4349218
198 Six 1973 All Blue P4349217
225 Six 1960 non Valiant Turquoise P4120752
225 Six 1970-74 All Blue P4349217
273 V8 - LA 1964-69 All Red P4349218
318 V8 - Poly 1960 All Silver P4529148
318 V8 - Poly 1962-66 All Red P4349218
318 V8 - LA 1967-69 All Red P4349218
318 V8 - LA - Police only 1968-70 Police engine H-Orange P4349216
318 V8 - LA 1970-74 All Blue P4349217
340 V8 - LA 1968 All Red P4349218
340 V8 - LA 1969 All Turquoise P4120752
340 V8 - LA 1970-71 All H-Orange P4349216
340 V8 - LA 1972-73 All Blue P4349217
360 V8 - LA 1971-74 All Blue P4349217
361 Golden Commando 1960 High Performance Red/Gold P4349218 / P4529149
361 V8 1962-64 All Turquoise P4120752
383 V8 1962-69 All Turquoise P4120752
383 V8 1970-71 All Blue P4349217
383 V8 HP/Police 1969-71 High Performance H-Orange P4349216
400 V8 1972-74 All Blue P4349217
413 V8 1962-63 All Orange P4120751
413 V8 1964 All Turquoise P4120752
413 V8 1965 All Orange P4120751
413 V8 Race Engine 1964 Race only Orange P4120751
426 V8 Wedge 1963 All Orange P4120751
426 V8 Wedge 1964 All Turquoise P4120752
426 V8 Wedge 1966-68 All Turquoise P4120752
426 HEMI 1964 Race only Orange P4120751
426 HEMI 1965-71 Street Engine H-Orange P4349216
440 V8 1966-69 All Turquoise P4120752
440 V8 HP/Police 1969-71 High Performance H-Orange P4349216
440 V8 1970-74 All Blue P4349217
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However. I'm thinking now, I'll just go with the Red.. most common, and most expected, i guess. Its not the original engine anyway, and the one in the Fury looks good. Thanks