I haven't been following all the posts on this topic and apologize if repeating someone else's observations. There are dip versions of the 74ACT160N that will do 100MHz over temperature depending on the manufacturer. The MC74act160N is a dip part available from Ebay at 10 for $10.00. The package is obsolete so unless you plan to buy safety stock it isn't for production. https://www.ebay.com/i/113374007747?chn=ps I resurrected my old Motorola FACT data book and: At 5V it is rated to 120MHz with 50p loading at 25C. It is rated at 100MHz over temperature. Since the absolute max voltage is 7 volts you could run it at 6 volts at even higher clock speeds. The MC74AC160N will not run at 100MHz over temperature and isn't available on ebay. I'd be curious to know how warm the part gets at those frequencies. Bob