The Master Parts Catalog has a good illustration of the door on page 585 called "Conventional Cab - Exploded View". It shows the "insulation" material sandwiched between the door skin and the braces. A 16.xxxx section number part number is not offered. Mine were rock hard When I knocked them out. The indention shows that the material was soft when it was pushed in there at the factory.

So I have the same question. What is a suitable alternative material?



1946 Chevy Half Ton
('56 235, '86 T5, '79 Camaro Z28 rear end, working on the '85 Jaguar XJ6 IFS)
1976 Margay Panther X, MC91B