The name here in Ether 1 is Shiblon (two times), but later on, in Ether 11, the name is consistently given as Shiblom (six times). There is evidence for both names elsewhere in the text:
There is also a measure of value with the name shiblon, which occurs four times in Alma 11.
Here in Ether 1:11–12, the 1888 LDS large-print edition made the text in Ether read systematically by choosing the later spelling Shiblom for the name of the Jaredite king. This emendation is consistent with the fact that there is no convincing evidence in the Book of Mormon text for two different spellings of the same name for the same person or group of people (as support for this conclusion, see the discussion under Alma 2:11–12 regarding the name Amlicite /Amalekite). Except for Shiblon /Shiblom, this identity also holds for every name in the Jaredite genealogy in Ether: the name that appears at the beginning of the book of Ether is the same name that appears later on in the narrative.
Earlier commentary on the discrepancy between Shiblon and Shiblom has noted the difference between Ether 1 and Ether 11 but without deciding between the two. For instance, Sidney B. Sperry, in a footnote on page 362 of The Book of Mormon Testifies (Salt Lake City, Utah: Bookcraft, 1952), states: “One wonders if, after all, we are not dealing with one original and not two distinct names. The Nephites doubtless adopted the Jaredite original, but we shall remain in doubt as to its correct spelling.” George Reynolds’ A Dictionary of the Book of Mormon (Salt Lake City, Utah: Joseph Hyrum Parry, 1891) lists the difference in spelling for the name as “Shiblom or Shiblon”. He does the same in his later A Complete Concordance to the Book of Mormon (Salt Lake City, Utah: 1900). And in the index for the 1981 LDS edition the variation is listed as “Shiblom [or Shiblon]”.
Stan Larson has argued that in the book of Ether Shiblom is to be preferred over Shiblon. On pages 566–567 of his article “Conjectural Emendation and the Text of the Book of Mormon”, Brigham Young University Studies 18/4 (1978), 563–569, Larson argues in favor of the more frequent spelling, namely, Shiblom, since there are six instances of Shiblom (all in Ether 11) but only two of Shiblon (both in Ether 1). Despite this argument from numbers, there is clear evidence that once a scribe started to misspell a Book of Mormon name, he would typically misspell it throughout a passage. For instance, Oliver Cowdery, when he initially copied the name Helam from 𝓞 into 𝓟 (14 times in the book of Mosiah), consistently wrote Helaman, even though 𝓞 apparently read Helam. Oliver later changed each of these instances of Helaman to the correct Helam (for discussion, see under Mosiah 18:12, 13, 14). A second example involves scribe 2 of 𝓟: in Alma 8 he wrote the name Ammonihah as Ammonidah for the first six occurrences of the name. Later Oliver Cowdery, when he proofed 𝓟 against 𝓞, made the correction to Ammonihah (see the discussion under Alma 8:6). Therefore it is quite possible that in Ether 11 Oliver Cowdery switched to writing Shiblom instead of Shiblon and ended up writing all six instances of the name that way. This change, if it did occur in Ether 11, would have likely taken place as Oliver took down Joseph Smith’s dictation since one of the six instances of this name in Ether 11 (the third one, in verse 4) is fully extant in 𝓞 and it reads Shiblom. Of course, one could argue that it was in Ether 1 that Oliver made the mistake of writing Shiblon instead of Shiblom. 𝓞 is not extant for any part of Ether 1, so the change there could have occurred in either 𝓞 or 𝓟.
In the same article, Larson provides a second argument in favor of the final m in Shiblom by referring to Hugh Nibley’s claim that “the Book of Mormon favors -m endings for Jaredite names” (as discussed on pages 248–249 in Nibley’s An Approach to the Book of Mormon, published as a priesthood manual in 1957 by the LDS Church): by implication, then, we have Shiblom in the book of Ether but Shiblon in the Nephite language. Of course, this does not explain the name of the Nephite general Shiblom in Mormon 6:14 (except to vacuously claim that it must be a Jaredite name).
More significant, in my view, is evidence from the manuscripts that Oliver Cowdery tended to replace the final n of Shiblon with the labial m, probably as a result of assimilation with the preceding labial b in the name. There are two examples of this error on Oliver’s part, both immediately corrected by erasure:
(For further discussion of these two initial errors, see under Alma 38:5.) These examples argue that if Oliver made a mistake in the book of Ether, the tendency would have been to misplace Shiblon with Shiblom rather than the other way around. The critical text will therefore assume that Ether 1 is correct in the name Shiblon and that in Ether 11 Oliver Cowdery misinterpreted Joseph Smith’s dictation of Shiblon as the assimilated form Shiblom.
This analysis leaves only a single occurrence of the name Shiblom in the earliest text of the Book of Mormon, namely, the Nephite general Shiblom mentioned in Mormon 6:14. Presumably, Oliver Cowdery was the scribe in 𝓞 for that portion of the text, and there he could have misplaced Shiblon with Shiblom one more time. Yet names do differ in minimal ways in the Book of Mormon, and they can end in om as well as on. For 26 examples of Book of Mormon names and words ending in on, see the discussion for the name Coriantor under Ether 1:6. For comparison, there are 16 Book of Mormon names and words ending in om:
The critical text will therefore leave unchanged the name Shiblom in Mormon 6:14. (For an example of four names differing minimally, see the discussion under 4 Nephi 1:47 regarding the names Amaron, Amoron, Ammaron, and Ammoron.)
Summary: In accord with the evidence from scribal errors, the name for one of the later Jaredite kings in the book of Ether should be consistently spelled as Shiblon, not Shiblom; it is doubtful that there are two forms of the name for this king since apparently no other name in the Book of Mormon allows for spelling variation in the original text.