Transmission swap NV4500 into 1982 W250

From : rick ellsworth

Q: looking for anyone who has made this swap or similar swap in older dodge pickups. right now were running 360 cid v8 built for torque with an old granny 4 speed. do you have to have an adapter to put dodge model nv 4500 axles are dana 60 front and rear with 4.10 gear ratio. truck is turning around 2400 rpms @ 45 mph. tires are 33x 10.5 will be switching to 37x12.5. can someone tell me what the difference would be on speedometer and approximate rpms with 2 tire circumference @ 45 mph. any help would be appreciated. rick .