tundra, if that 041 is 61 cc (3 different 041 sizes were made, I think), I guarantee you it didnt have even close to 5.5 hp. That is over the rating of the appx 72 cc 044 and 372 Husky, which have way more power than that old 041, for sure. And weigh in about three pounds lighter.
When I was foreman for a tree service back in 77-84, the largest saw we had was an 041 (I dont know which one) What a dog it was!! After a few yrs there, of renting/borrowing a bigger saw from a friend, I finally got my own 045Super, a heck of an improvement.
By the way, if you go to Stihl's Brasil site, and a couple other countries, you will see, still for sale amazingly, the 051, and the 038. No 088 or 090, tho. But I think the 090 is still available down there.
I recently ran an 075, which pulled the 42 bar with chipper chain just fine. What awesome low end torque!!!