Most of the bomb guys who are into "OG" will tell you to leave your ride stock and just lower it. The problem with that is that the old suspensions were never designed to be lowered or to ride like newer vehicles, and the technology from 70 years ago just doesn't compare to that of today. The old suspensions and roads were completely different, and car builders had no idea about adding hydraulics or, as in this case, airbags to their rides.
After being asked how to "bag" a '39 Chevy, we started asking around and wound up talking to Adam over at Master Image Customs AKA MIC in Chino, California. He told us to come on down as they're always working on these types of cars. Adam explained that the best way to lift or bag a bomb was to add a Ford Mustang 2 front end, which also makes it easy to add disc brakes. The install is something that an experienced guy can knock out himself in a day or two, depending on his suspension and welding skills.
We caught up with the boys at MIC, who showed us how they modernized a '37 Chevy Fleetline. This suspension remained the same through 1939, which makes it the most common suspension on Chevy models of that vintage. Now follow along as MIC shows us how they "masterfully" retrofit a classic using modern technology.
 MIC first removed the complete...  MIC first removed the complete front leaf spring suspension. |  The engine crossmember is...  The engine crossmember is unbolted and pried off. The bolts were then cut and the frame was ground smooth to allow for the new crossmember to be welded on. |  This is the crossmember that...  This is the crossmember that will replace the old engine crossmember, as well as support the new front suspension. |
 The crossmember was centered...  The crossmember was centered following the instructions for the front clip. |  The center was then clamped...  The center was then clamped to the frame on both the driver and passenger sides. |  |