My 78 express again, but now with a modified stock muffler. Intake bored out as well as exhaust port enlarged. Running a stock carb from an 81 express, Did a plug chop and it’s looking good so far but might up jet and see if that improves it a bit more. I know it’s hard to see, but not easy to ride one handed at that speed on an express. The road is pretty flat but had a tail wind. Going down a different road with a downhill slope I hit somewhere around 38 to 40. Difficult to tell as the speedo stops at 35mph.