plug gap with TW heads?

88_GT_5_oh

Sportin' a turbo 5.0 in Canadistan
Jul 4, 2004
1
0
1
WPG/MB/CA
what should my plugs be gapped at for my Twisted Wedge heads, i am looking on the site but can't find the info, it just says what plugs to use, car is idling kinda rough but runs great on the street, just trying to narrow down my search

BTW i am using NGK-FR5 plugs