1. Hom. uses the open or the closed forms according to convenience. -ευς occurs in the gen. of a few words in -ος (βέλευς); -εων is often a monosyllable ( cross60), as is the accus. sing. and pl. -εα from nom. -ης or -ος. Hdt. has open -εος, -εα, -εες (?), -εα. In the dat. pl. Hom. has βέλεσσι, βέλεσι, and βελέεσσι ( cross250 D. 2) from βέλος
2. Stems in ας are generally uncontracted in Hom. (γήραος, γήραϊ), but we find -αι in the dat. sing., κρεῶν and κρειῶν in the gen. pl. In the nom. and acc. pl. α is short (γέρα), and this is sometimes the case even in Attic poetry (κρέα). The explanation is obscure (γέρα does not stand for γέρα'). Hom. has δέπασσι and δεπάεσσι (δέπας
3. In Hom. and Hdt. several words in -ας show ε for α before a vowel (cp. ὁρέω in Hdt. for ὁράω). Hom.: οὖδας
Herbert Weir Smyth [n.d.], A Greek Grammar for Colleges; Machine readable text [info] [word count] [Smyth].