Gauge was totally off due to much bulkier yarn, so I adjusted the pattern:

CO 48 st. Knit rib (k1, p1) for 6 cms. Continue in stockinette, increasing evenly to a total of 55 st.

Place stitch markers after 20, 8, 19, 8 st.

Start raglan increase every other round, picking up 1 st before and after every stitch marker. Repeat 5 times. Continue with the increases every 3 rounds until you have a total of 166 st. Put 35 st for each arm on a separate needle and cast on an additional 8 st under each arm hole. Continue on the yoke, knitting the arms later.