Engine swap 2003 into a 2009 Forrester

Longer story but short is that I blew my engine on my 2009 Forrester and it needs to be replaced. I have a friend who has a wrecked 2003 Forrester and I have that engine that was pulled with everything attached in case it was needed. It was running well when pulled out last weekend. However, I can't get a straight answer if that older engine will fit in my 2009 vehicle? Anyone know these things inside and out and can let me know.

The 2003 VIN #JF1SG656X3H764762

2009 VIN# JF2SH64669H765037

Heard that the engine model went from a 'xxxxxxG' in the 2003 to a 'xxxxxH' model designation in the 2009 or something like that so I'm hoping it's a minor change.

I was told that the 2003 would definitely drop right into up to a 2008 but is questionable into a 2009. Not sure if that's convenient BS from the mechanic who wants to sell me an engine with his markup added instead of installing what I have. I'm hoping somebody can explain the differences and give me a definative answer.