If we are talking 1941-45 Chevy 235 GI trucks, the intake/exhaust manifolds are the same as civy excepting a hydrovac port and PVC system on 1943-45 models. Early trucks had no provisions or design for high water driving.
Personally I think the cast iron piston GI 235 sounds like a diesel when at idle, but I would imagine a similar year civy should sound the same. GI 235's share more common parts with civy trucks than not and the unique GI parts would not contribute to a difference in sound.
Paul
Last edited by Paul_WNC; 12/21/2015 12:54 PM.
