Looking for some help in ID’ing a distributor (one on the left). The one on the left has a W1218 printed on the side of it but a google search turns up nothing. I believe it is an MSD but didn’t know if it was an small block or big block. I think there is only a 1/8” difference between the two in the length under the mount. Any help with an actual part number would be great. Just looking to see what it is worth.

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'75 Plymouth Duster
Phase I 451 906/590/2-660 10.75/126
Phase II 451 Stage VI/590/1050 9.82/135
Phase III 383 906/Victor-Pump gas 11.30/119

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