Customizing latest SILVA for V4

Hi mothur team,

I am processing 16S V4 data (515F/806R, ~253 bp reads). I want to customize the full-length latest SILVA v138.2 reference database to create a streamlined V4-only reference file.

What are the recommended exact start and end coordinates to use in pcr.seqs for the SILVA v138.2 database?

Thanks for help,

Richa