Sorry, I don't have any data, but I'll toss out these words of wisdom:
While wildcats can be fun, they aren't standardized and you're on your own for working up load data. There's no telling how many 'improved' .270's out there, with different shoulder angles, body diamters, and throat lengths. Even if it's an "Ackley" improvement on a standard .270 Win chamber, there may exist more than one variant.
Having said that, when you open up a chamber and take out more metal to increase powder capacity, one thing that you can be sure of is that the pressures will drop as compared to the original loading. So, a good starting point for your improved .270 Win load development would be near-maximum .270 Win loads for the standard cartridge, and work up with a chronograph and good micrometer. Clearly, not a good place for a novice handloader to be.
Do check out Ross Seyfried's article on pressure in the latest Handloader. Might give you an idea if you feel up to tacking such a project.
Best of luck.