Definitely taking the over
I wouldn't be so quick to jump on the over tonight simply because it's such a public bet. That being said the number will trend upwards as the day goes on so if you like it I would put it in now. By tip tonight it'll be somewhere near 148 or 149.
Iowa State averages 79ppg
Oklahoma averages 72ppg
Total: 151
Oklahoma @ Home Averages 74.26
Iowa State is averaging 74ppg on the road in their 4 conference games this year and has a record of 1-3.
Total: 148
One thing I will say is that if you look closer into those games there's been a ton of points scored in the last 5 minutes of those games. Whether it be because of fouling so that we can give ourselves a chance to come back (Kansas + Tech) or whether it be a game that's been called extremely tight (@WVU and @Baylor)
Lastly, I went back 5 years and looked at all the games against OU and we've only been held to under 70 points one time and we still scored 69. Different players obviously but the games were still all pretty close in score and averaged close to 150 ppg.
Good Luck with whatever you do- I'll sit back and cheer for an ISU victory no matter the score.