The block casting date code E 11 6 decodes to May 11, in a year ending with 6. Could be '66 or '76. Most sources give the year range for that 292 block casting number as '63-'76 (most online sources just copy the info from Inliners), but I found one source that only went through '72, and after '72, the casting numbers were very different. Yours could be a '66. There was also apparently a change in 292 heads in '67. Can you find the head casting number?
The engine serial number you give doesn't appear to be a serial number. Was this number stamped on the pad to the rear of the distributor? It should be in a form such as F0503WA. While the engine serial number won't indicate a year directly, the suffix code can provide clues. For instance, regardless of what the suffix decodes to, a 2-letter suffix would indicate a year in the '63-'69 range, and a 3-letter suffix would indicate '70-up.
