I my '68 Barracuda matching numbers?

I bought this car 3 yrs ago and the owner said it was an all original,
matching numbers car. 1st owner, a woman in California, 2nd guy he bought it from down his block (Colorado), then me.
Car wasn't cheap.
Had some work done yesterday by a member of my local Mopar club
who used to be a mechanic for Dodge years ago and he thinks car is not
numbers matching because part of VIN# is not on motor.
BUT he also said that it shows my motor was cast in 6-19-67
and VIN matching started in '68.
Confused and a little disappointed!
Can you guys shed some light?
VIN: BPH29P8B129717

MOTOR: 6-19-67 DW340 2226 0100

TRANS: PK2892032J 2225 2497

Thanks!