I will 2nd Kevin's info about the block casting number "3764476".
Can sorta read bits and pieces of the casting date code: 1st character "B" (possibly), followed by "2" and an unknown (those 2 numbers would indicate day of the month) and ending with what looks like "9" (which would signify the year 1959).
My resource book indicates this casting number identifies '59-'62 235 with 135HP rating, but doesn't say type of vehicle (truck/car???).
Jerry is right that the key number we need to know will be the stamped character set on the machined pad directly behind the distributor location.
On the color orange you mentioned, I am not seeing anything actually painted orange in your pictures of the block and head. Just orangish rust. If there is orange paint anywhere else, it won't be original paint for your truck.
Get back with us when you can with the engine ID stamping data and we can provide better info.
Dan
