I have a 39 now and have owned several 38's in the past. Don't have a 38 nearby for comparison, but from what I recall the 39 frame is very close to the 38 and should be a relatively easy fit. If your car and the donor are both straight axle models, the front cross members are the same, but they are much different between years for the Master Deluxe models. The 38 and 39 frame curves over the rear axle are the same so inner fender panels fit well. If the 39 is a business coupe (no rear jump seats) the gas tank is on top of the floor where the rear seat is in your sedan. You will need to re-use your 38 cross member in front of the tank to mount the tank. You might want to keep the coupe cross member for trading as it is only used on the coupe and sedan delivery. The other major frame difference is the style of the the rear mounts for the rear leaf springs with the 39 going through the frame, but I think the mounting holes can be patched fairly easily for use on the 38. There are other small differences such as mounting for the parking brake linkage and perhaps the steering box mounting, but I think all major frame dimensions and body mount locations are the same. Good luck.
1939 coupé frame for sale and would like to know if it will work with my 38. Out of curiosity what are the differences if any?
