I believe our pitch is something like 115 x 80, which is the largest in the SPL, closelyfollowed by Ibrox at 115 x 78 (although I believe they may different dimensions registered for European fixtures)
The figures I have are a couple of seasons old, but here they are for each club
Aberdeen - 110 x 72
Celtic - 105 x 68 (again they may be diff for Euro fixtures as I think it needs to be min 110 length)
Dundee Utd - 110 x 72
Dunfermline - 115 x 71
Falkirk - 110 x 72
Hearts - 107 x 74 (lack of length caused all the probs with them holding Euro fixtures)
Hibs - 112 x 74
ICT - 115 x 80
Killie - 115 x 74
Motherwell - 110 x 75
Rangers - 115 x 78
St Mirren - 110 x 70