la vs magnum

The LA should sonic check better in the bores...but I would check them! You want the thickest bores you can get...and the early blocks have thicker main saddles which help keep things where they need to be.
If you'll exceed 650HP, I would recommend an R3 if Indy has any left.
Brian

r3 block wow... i kinda fall right back into cost again lol. i guess horsepower costs either way i look at it. what type of power is a good stock block able to handle? do all r3 blocks use a dry sump oil system? sorry for all the questions. my main reason is to build a driver but a weekend warrior as well. i am hoping to break 700 as putting boost to a engine only makes it easier.