Today, dollar for dollar, is the 318 faster than the 340 ???

What if you have both (318/340) "sitting around" collecting dust and insect nests....the cost is the same across both, gasket set, timing set, cam, oil pump, rings, blah blah blah machine work...etc. then which, all things considered one would you build? (yes there are folks who have multiple engines siting around in their garage).
If my aunt had balls she'd be my uncle