Difference between STI version 4 and 6 block?
 

hi as title is there any difference and which is better?

V4 is Centre thrust and has 4 bolts for the 752 gearbox, V6 is end thrust and has 8 bolt holes for the 754 gearbox. V6 is better due to the thrust bearing location but the cranks are not interchangeable

recently bought the v4 type r, just been looking through my invoices and have notice it has had a v6 block when engine was rebuilt.

are there any advantages in having a v6 block? performance or reliability wise?

Performance wise, no, reliability wise, it is slightly better hence why they changed the bearing location

The last few months production of the V4 switched to rear thrust blocks