It's 3 shots in the body for the APSFDS-T shells, 2 in the head though I think.
I'm loving the LAV more than ever, happy to take it instead of a tank. It's harder to get critical hits on tanks/lavs/boats with the TOW now though.
Plus the speed of the TOW is so good, I'd say it's almost on a par with the pre-patch Sraw, minus the range. Shooting down air vehicles is almost too easy with it now.
When me and Patsy go in LAV we seat switch (him with zunis and AP, me with TOW and smoke), the other LAVs look very confused, they see the zunis, rush to engage and then eat some TOW.