This is my first time posting on here i am orignally from Plymouth but i moved to California 5 years ago.

Well here's my problem. I bought a Jap ver7 engine from a vendor over here and when i got it, things seemed a little fishy to say the least.
The engine came with no tags on it and all that looked to be STI was the red intake manifold & AVCS

I called the vendor with my concerns and they assured me the engine was legit.

I installed the motor in my 02 WRX with VF34 565 pink injectors and the JDM< spec c ecu.
Everything was fine for about 3 weeks and then I noticed the engine wasn't as powerfull.

Last week I saw a post from a guy who had also purchased the same engine and he took the intake manifold off to see if it had the big ports and it didn't!
I then checked mine and it was the same, small ports.

We came to the conclusion that these engines were UK spec STI engines.

Do the Jap and UK engines have the same cams?
Do the UK STI's have the butterflys in the intake manifold?
What is the rev limit of the Ver7 UK STI?
Does anyone know what the codes are on the UK STI heads Mine are LHS20 & RHS20. I believe the STI's Have LHS20V?

Any help would be great

Cheers Stuart