you can safely upgrade from a lower VA rating to a 40VA unit

For horizontal piping

Common Questions How do I adjust the draft setting on the 4" MG1

The unit features overpressure protection with a proof pressure of 15" WC and a burst pressure of 23" WC

and 4363369

Modine 5H0731000002 Gas Valve Freon you can safely upgrade fromThe Modine 5H0731000002 Gas Valve is a technical grade OEM replacement gas valve engineered for critical pressure regulation in high capacity heating units. Supporting a primary 24V gas valve architecture, this component is factory set to a 3. 5" WC (Water Column) manifold pressure, ensuring precise fuel delivery for optimal combustion efficiency. As the direct updated version for 5H73100 2, it maintains a drop in 1 2" x 3 4" NPT connection profile,