Interestingly and despite the difference in displacement, both engines have similar power.
For a nice scale project like the Gilmore, I would personally stick with something like the MVVS rather than the DLE55 some have suggested. You will get better low-down torque out of the MVVS which in my book lends itself better to scale applications. If you stick a pipe on the 40, you will also get a very nice quiet setup (if there is any such thing)
I'm in no way knocking the DLE, it's just my personal view.