The RV dealer where my MH is stored had both replacement heads so I purchased the new Winegard Razor head replacement kit. The razor antenna is physically larger the the Jack antenna.
I would suspect elements inside for VHF would be slightly larger than in the Jack. With equal ability to get signals off front and back it overcomes the dead space to rotate antenna directly at a tower.
Hopefully amplifier circuitry is similar to Wingard Sensor antenna heads. I expect my second adjustable (2 to 10 dB) amplifier to work well with the Razar as it did with my original head.