I have classified John R. Rice as a historical premillennialist, but contra some of that stripe he was also pre-trib. He was definitely not a dispensationalist. He respected Scofield, but disagreed with him in his books and sermons numerous times. His number one disagreement was his belief that the church did not begin at Pentecost. Also, he included the OT saints in the church.
Following him in this belief got me in trouble when I applied to my mission board, which was dispensational. In my application, I said concerning the doctrinal statement that I did not agree that the church is "peculiar to the age of grace." They sent me to Dr. Monroe Parker, a true fundamentalist scholar, and I spent a day with him, then left convinced by his brilliant arguments that yes, the church is peculiar to the age of grace.
I then joined the board and was sent to Japan. On the way there we stopped in CA at a church, and stayed with a guy who grilled me on my theology. He ended up saying, "I'm telling your mission board that you are not a dispensationalist." I shut him up with, "They're the ones that told me that!"
Concerning Hyles, I had thought that he was a dispensationalist. I have very few books of his nowadays. I got rid of a ton of all sorts of books when we moved back to the States. However, I have the weird book by him,
Enemies of Soul-Winning, in which he proved that he did not understand dispensationalism by attacking Scofield as an "ultra-dispensationalist." Hyles was nowhere near to being a theologian, so I recommend ignoring anything he said doctrinally.