OK couple of questions to get peoples views....

I've had a rebuilt forged 2.5 fitted to my 2002 WRX - original spec was 2.0 WRX engine with tumbler deletes, pink injectors, Walbro 225 fuel pump, K&N panel filter 3' Miltek sports catted exhaust, APS SR40 turbo, Sti TMIC, APS dual port BOV and Perrin Parallel fuel rails. This was JGM mapped on ECUtek to 370BHP.

The new engine is a fully forged 2.5 with STI 8 AVCS heads I've also swapped to a HDI FMIC and CAK intake - my plan is to very slowly drive the car home without a remap - (about 40 miles) is this wise? The engine is then being remapped onto syvecs before I use the car again.

Once on a running in map what's the best way to treat the engine - I know I need to do around 500miles on mineral oil with low boost (<4K) varying the engine speed and not using full throttle. Any other tips?

 

You should be fine to drive off boost.

I would go with your engine builder's advice for the running in method.

Personally I prefer to run them in harder than.