It doesn't necessarily have to be a big band, just a larger group (6 or more musicians) playing free jazz is what I'm looking for.
A few examples of bands & albums that demonstrate what I'm talking about: Cecil Taylor's 'Unit Structures', Electric Masada, John Coltrane's 'Ascension', Noah Howard's 'The Black Ark', Ornette Coleman's 'Free Jazz', Peter Brotzmann's 'Machine Gun' & Sun Ra's Arkestra. Bonus points if they have a good guitarist.

Not sure if this kinda suits but GOD is a 9 piece band that a various points featured Justin Broadrick and John Zorn. Check their album 'Possession', its a hard listen. Its kinda free jazz, a bit of metal and noise.

Joe McPhee ‎– Nation Time (1970)
http://www.discogs.com/Joe-McPhee-Natio ... se/1149290
https://www.youtube.com/watch?v=Y0ItcjG3BgY


Manfred Schoof ‎– European Echoes (1968)
http://www.discogs.com/Manfred-Schoof-E ... se/1900032
https://www.youtube.com/watch?v=8wurRN0zY2o


Globe Unity Orchestra ‎– Globe Unity 67 & 70
http://www.discogs.com/Alexander-Von-Sc ... se/1114725
https://www.youtube.com/watch?v=hg3Ah92O2wg


Peter Brotzmann Chicago Tentet - Octet Tentet (1998)
http://www.discogs.com/Brötzmann-The-Chicago-OctetTentet/release/1151323
https://www.youtube.com/watch?v=HtWHFDb193Q


Randy Weston - The Spirits of Our Ancestors (1992)
http://www.discogs.com/Randy-Weston-The ... se/2661884
https://www.youtube.com/watch?v=BNxW8WQmduU


have fun!

Thanks for the recommendations, have heard of 'God' & 'The Globe Unity Orchestra' but never listened to any of their music, and I've listened to bits & pieces of stuff from Peter Brotzmann's Chicago Tentet, thanks for the recommendations! I look forward to checking everything out & please keep them coming!