Correct the collector-MAP section is a little larger. Pretty sure 4mm for 3 TBs and 6mm for collector-MAP
Mine are in a box somewhere and im too fat to get up now lol but I can say I replaced them all with 4mm vac tubing from local autoparts store.
For MAP I needed to step it up slightly so guessing 6mm
Be careful though some 4mm tubing is not vacuum tubing