440 what am I missing here?

Sorry not much help, but I would really like to se a pic of the big block under the hood.
I have a 46 dodge truck, that I bought a few months ago, and the previous owner said he could not get the flat six running.
I have not tried to get it running yet, but I do have a bunch of big blocks looking for a home.
How much did you have to modify the firewall?