Steven, that option would be best for your pocket yes, just make sure it's late sec engine as the spec changed every year and the latest were deffinately the best

The problem with a wrc engine is there is so many measurements to be taken whilst mapping. For example post restrictor pressure more commonly known as restrictor depression. Turbo speed. Detonation which is so easily found on a 11:1 cr engine with 40psi boost. It's so much better to map every point on a dyno to get a 95% map then check in the most commonly used load points in the car.

IMO you cannot properly map every point in the car from a base map. But only the most commonly used points which are found whilst mapping on a certain day in certain conditions. You only have to have a few weak points and a couple of points with 3deg too much ignition that will cause a crack of det and slowly nibble away at the pistons and head.

This is of course my personal opinion but it's the right way to do things.

Jim