This study examines dynamic acoustic-articulatory relations in back vowels, focusing on the effect of different coda consonants on acoustic-articulatory dynamics in the production of vowel contrast. This paper specifically investigates the contribution of the tongue and the lips in modifying F2 in the FOOT-GOOSE contrast in English, using synchronized acoustic and electromagnetic articulography data collected from 16 speakers. The vowels FOOT and GOOSE were elicited in pre-coronal and pre-lateral contexts from two dialects that are reported to be at different stages of back vowel fronting: Southern Standard British English and West Yorkshire English. The results suggest similar acoustic and articulatory patterns in pre-coronal vowels, but there is stronger evidence of vowel contrast in articulation than acoustics for pre-lateral vowels. The lip protrusion data do not help to resolve these differences, suggesting that the complex gestural makeup of a vowel-lateral sequence problematizes straightforward accounts of acoustic-articulatory relations. Further analysis reveals greater between-speaker variability in lingual advancement than F2 in pre-lateral vowels.