load Int64.Type as type text first , what are consequences ?

Hi All

it is advisable for me to load Int64.Type as type text first ? what are consequences ?

let
Source = Csv.Document(File.Contents("C:\Users\pauly\Dropbox\QV_RAW_ISDN\AR_TS_10.txt"),null,{0, 9, 99, 119, 126, 161},ExtraValues.Ignore,1252),
#"Changed Type" = Table.TransformColumnTypes(Source,{{"Column1", type text}, {"Column2", type text}, {"Column3", type date}, {"Column4", Int64.Type}, {"Column5", type text}, {"Column6", type text}})
in
#"Changed Type"