Originally Posted by jura11
GDB STi Type RA(or if you want Spec C) using different heads,which have different part number as Big port heads
Big port heads which are on V7,V8 or V9 have usually part number on heads LHS20 or RHS20)
Spec C in opposite way using different part number(LHT20 or RHT20,but some people saying they're using LHC20 or RHC20,but we are bought S204 heads which have part number as above LHT/RHT)
But from v7 JDM WRX(EJ205) using same Big port heads just there is difference mainly in cams which are used
Hope this help
If your posting refers to UKDM Sti, and the way they compare to JDM engines, please clarify that.
In any case, GDB Type RA and Spec C Type RA are two different cars. There is nothing for me to choose, because they are different timeline wise and engine wise.
Type RA uses a different cams than Spec C in revision A. They should not be confused.
Also, "big port" is a vague designation.
All the JDM Sti are "big port".
If you look in my posting, you will see that, although the Type RA (and NOT the later Spec C Type RA), already had big ports, they did an additional radius smoothing.
Take a look at the technical drawing provided, it will help with ID-ing those engines.
Now, as far as the Type RA and Spec C Type RA having different heads than their contemporary JDM Sti, this is incorrect.
All you have to do is go and look up the part numbers for, by example:
2001 JDM Sti and 2001 JDM Sti Type RA
Same part number.
Now the radius smoothing was a process said to be done after the heads were machined.
If you meant to compare the Spec C with an UKDM Sti, please specify this, otherwise causes confusion.
The LHS and RHS are casting and assembly codes, but not part numbers.
A Subaru Part number has a format as the example above (1139AB370).
Using these instead of part numbers is a good atempt of creating useful information for enthusiasts, if you have more info of this nature please post it.
It's possible that some in UK consider thet the UKDM EJ207 from an UKDM Sti and the same year JDM EJ207 from a JDM Sti, are one and the same engine., but they are not.
First Sti Type UK in '02 had heads: 1109AB440
The '02 JDM Sti 1109AB370