I used 30# Roofing felt, "glued" on with Plastic Roofing Cement- (Ashphalt & Fibreglass), on the roof, and under the seat, and felt under the floor mat. It made a huge difference, still loud and "truck-ish", but much less tin cannish. That and new weatherstrip.
Christopher.

Christopher
1950 1-Ton
"Rochester"
In the Gallery
In the DITY Gallery

1949 GMC Panel Truck
1926 Model TT Truck