The SPFL League One champions take on their Championship rivals at Easter Road on Sunday and McCoist is expecting a difficult match.
McCoist said: "I was through in Edinburgh last Tuesday watching the Rangers Under-20 side and had a good chat with big Terry Butcher.
"Terry will tell you as much as anybody that Raith ain't bad as they knocked Hibs out of the Scottish Cup at Easter Road this season.
"Raith are definitely a good side. I have watched them a couple of times myself. I think they are actually far better than their league position (the Kirkcaldy club is seventh in the second tier) suggests.
"I saw them against Dumbarton in the Championship and against St Johnstone in the Scottish Cup when they should have been 2-1 ahead. They had a couple of chances to score at 1-1.
"It is, no doubt about it, a proper game. We are looking forward to it as, for that matter, are Raith. We are in no doubts that it will be anything other than a difficult game."