trying to build my own shortblock, building it for boost. I cannot find a decent aluminum block to save my life. I'm on a budget, and I was curious if this is a good route http://www.fordracingparts.com/parts/part_details.asp?PartKeyField=6363 . I know cast iron is suppost to be more durable, so my question is how much work to machine this to accept the 4v heads and internals etc...? HELP! Thanks