I have a very big DOOM 1 map ready for playtesting. It is a BOOM compatible map and I tested it with PrBoom. I used the original DOOM 1 IWAD doom.wad. The map is called 5spiders and is a single level on E1M1. Playing time is between three and four hours. It is intended for advanced players that know their way around an old-style map.
The complete TXT file with all additional information is with the wad in the zipped attachment.
If you would like to give it a try and send me feedback,