ASCII File Transfer Records Truncated to 80 Bytes

I am trying to transfer an ASCII file using ASCII file transfer to an IBM Main Frame. The orginal record lenght of the file is 460 bytes but when the file transfers the record lenght of the file is truncated to 80 bytes for each record. Anyone know how to transfer the file and keep the record lenght? I can't transfer in binary format as the program that operates on the file will not read it as it must be in ASCII format even when the orginal is ASCII the binary transfer does something to the file. Thanks for any help.