The rear and front cross members are the same on 26/27 model chassis. The front crossmember was modified to accept the newer fender brackets. Also, the 26/27 chassis was designed to give a lower appearance. Earlier chassis had minor variations like hand brake quadrant, running board bracket length, fender irons etc.. It kind of depends on how original you want to make it. Personally, I would look for a '26/'27 chassis and keep it as original looking as possible. Just my opinion and good luck.