One book shows only 1971 chevelles were made in Arlington texas,does anyone know if a 1970 model could have been made there also,possibly late in the production cycle?

Afraid your book is incorrect. Arlington produced Chevelles from 1970 through 1972. Here are four examples of 1970 body number plates (http://www.chevellestuff.com/70velle/70_trim_tags-bt.htm) from Arlington from at least February or later, and a couple from 1972 (http://www.chevellestuff.com/72velle/72_trim_tags-r.htm) as well.

Thank you graemlins/hurray.gif