Are you sure you read the head casting number correctly? My '68 parts book shows 3864888 as a head for a 153 4-cyl. of approximate '63-'65 vintage.
If it's really 3864883, that would be for a 194 head from '64-'67. There is also a 3864886, for a 230 head from '65-'70. The closest 292 head number would be 3864890 for '63-'66. This info is from
here. The date code H154 would translate to August 15, probably of '64, if this head is any of the above.
Your block ID suffix XXF doesn't show up in my suffix lists through '72 for cars or light trucks (that's all the farther my info goes). If XXF is a legitimate 6-cylinder suffix, and it follows the normal format, a 3-letter code would be from a '70-up engine. Have you found any block casting numbers, or the block date code?
Edit: The XXF suffix may be a crate motor designation, meaning an engine sold "over the counter" as a replacement.