520 ci possible block issues

[mojavered]

Using a 70 440 block, what kind of clearancing issues are going to be had making an engine into a 517-520?  Is a main girdle something to be considered here?  At what kind of horsepower do you start to worry about putting a main girdle, unless there is a better way, on yout bottom end?  By the way, it is a 30 over block and I guess that would be all the info needed at this time. 

[moparniac]

If you plan on making over 650HP I would girdle it.... I would atleast stud it regardless!...... However if your gonna girdle it they required main studs so when you get your block machined use main studs! You will have to grind the block some for crank clearance with a 4.250 stroke crank.... BTW 4.375 bore and 4.250 stroke is a 511  Getting a good block is a plus..

[Chryco Psycho]

512 requires minimal clearancing assuming you use a good quality crank , if you go much biggger you can have issues with the oil pump pickup & may have to go to an external line .
 for most sreet application you should be fine without the girdle as Jason said

[moper]

 
Yup. What they said. 4.25 stroke, use the Chevy pin size, and there is no interferance with the internal pickup boss except in a few instances.