Valvetrain Width

When I make a new engine for a car, after deciding on layout, I almost always have to chose the valvetrain first (second tab) before chosing the cylinder bore.
Otherwise the size arrow will turn red when I go to the second tab and decide, and I have to go back and reduce the bore.

Can you make it so that when the top end is empty, the game assumes that the length of the engine will be with the widest valvtrain (DOHC 5v i think), until you actually make the choice?

Technically that’s not easy to do because the bounding boxes are loaded in with the selected items, but yes, that is an issue in general.
I fear though that it is an issue that cannot be solved and appears in aspiration and exhaust too. Players, until we find a better solution, have to get used to the workflow of determining the rough size they aim for first, then complete the engine and then fine-tune size.