I don't have a db meter but I just finished my sound proofing project, well almost I have to do the firewall yet. 1 layer of brown bread on the roof 2layers on the floor, cab back,doors. 1 layer GSI foam on everything but the roof. It worked I think it's only about 1/2 as loud as it was before. No more road noise,I',m very happy. A little work on the cowl and firewall and maybe I can be done working on it for a while,but I will find something else to do.
Later Mike

Later Mike