It's been so long since I built a car model engine, that I completely forgot certain basics, one of which is to make sure that things are square. Given the sometimes extreme draft angles of the injection parts provided in a lot of car models, certain items frequently need to be squared off before assembly. In this case, I did remember to square up the tunnel ram, but not the top of the block itself. As a consequence, the tunnel ram perches on a pitched block top that will now require some filler to make look right, or at least OK, and could have been easily resolved beforehand, but was not. Live and learn, I guess.