From the 1977 FSM courtesy of 91PowerRam.
Ramcharger
front frame--29.88" wide outside of frame rails
4.00" tall inside the frame rail
rear frame--37.68" wide outside of frame rails
5.55" tall inside the frame rails
side rail section--6.06" tall
2.27" flange
0.156" gage (thickness)
D100-D400
front frame--30.30" wide outside of frame rails
4.00" tall inside the frame rail
rear frame--37.68" wide outside of frame rails
5.55" tall inside the frame rails
siderail section --6.06" to 7.20" tall depending on body style
2.27" to 2.79" flange depending on body style
0.156" to 0.250" gage (thickness) depending on body style
W150-W400
front frame--29.88" wide outside of frame rails
4.00" tall inside the frame rail
rear frame--37.68" wide outside of frame rails
5.55" tall inside the frame rails
siderail section --6.06" to 7.20" tall depending on body style
2.27" to 2.79" flange depending on body style
0.156" to 0.250" gage (thickness) depending on body style
Ramcharger
front frame--29.88" wide outside of frame rails
4.00" tall inside the frame rail
rear frame--37.68" wide outside of frame rails
5.55" tall inside the frame rails
side rail section--6.06" tall
2.27" flange
0.156" gage (thickness)
D100-D400
front frame--30.30" wide outside of frame rails
4.00" tall inside the frame rail
rear frame--37.68" wide outside of frame rails
5.55" tall inside the frame rails
siderail section --6.06" to 7.20" tall depending on body style
2.27" to 2.79" flange depending on body style
0.156" to 0.250" gage (thickness) depending on body style
W150-W400
front frame--29.88" wide outside of frame rails
4.00" tall inside the frame rail
rear frame--37.68" wide outside of frame rails
5.55" tall inside the frame rails
siderail section --6.06" to 7.20" tall depending on body style
2.27" to 2.79" flange depending on body style
0.156" to 0.250" gage (thickness) depending on body style