I saved the following dimensions from a source I no longer remember and I'm sorry to say I don't know the exact points the length measurement was taken from. These numbers are from a 250, but the only difference would be the height, if I'm correct.

Chevy 250 external dimensions

L = 32.5”
W = 16” (23 W/MANIFOLD)
H = 24”
Wt = 410 lbs