[Matt Monson]

If it were me I wouldn't go all the way to the 2.7. I would personally stay away from modifying the case for the bigger displacement. If it were mine, I would build it as a 2.5l with 1mm overbore on the cylinders and some JE pistons. Single plug. Low 9's compression with a Solex ground cam.

And just keep all the original parts in boxes on the shelf for if you ever sell the car. You never know what the next guy will want to do with it, unless you plan to make the car your coffin when you check out.

To answer the root question, I think what I suggest is a zero sum game for end value. I think if you modify the case you will devalue the car in the eyes of certain potential buyers. But it's a very personal question. I am reminded of the discussion we had last summer about inoperable AC. For a sizeable group of people the AC not working is a big hit on the car and they wouldn't even contact the seller unless they felt the car was already discounted. For others, it meant nothing because they would rip it out anyway. Engine mods become like the same sort of thing.