I recently got a new b18b block for my stcok ls. But the block comes with P73-AO (which are for USDM Type R, or thats what i´ve been told) instead of the PR-4 that would be ls stock ones.

Then my comp should go from 9.2 to 10.3. I know that much, but Is there anything that I should modify or take particular care of. Do I really need to do a tune for such a small difference and what do I have to do?

Thanx all for your help, the engine is being installed right now so I will really appreciate your comments.

 

Yes you should have it tuned. Thats a good jump in compression. Also personally I would no longer use 87 octane either.

 

true, u need to use 91 or higher octane with those pistons

 

Morning Bump!

 

Probably want a little more cam and fuel in there as well. Also open your spark plugs up a bit.

 

It would be nice if someone could tell me exactlly what I need to do to the car, Ì'm totally ignorant about mechanics so It would ba great help. That way I can make sure that the mechanic actually does everything he needs to,
Thanx.