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5.9 Magnum block vs 360 LA block....

1 Wild R/T

FBBO Gold Member
FBBO Gold Member
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5:24 PM
Jul 9, 2019
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I'm looking at building a small block for a friend.. Currently he has a 340, it needs everything & we're talking about going to a stroker kit.... The one thought I have is using a 5.9/360 roller block rather than the 340.... Let the resto types buy the 340... So, what I'm finding is the 89-92 360 roller blocks are getting harder to find but 5.9's are everywhere....

We already have LA style heads & rockers.. I'm wanting to put a 360 stroker kit in a 5.9 block... About the only thing I keep reading about that's different is the 5.9 has a shorter deck height... So I searched for the stock deck height spec... 5.9 Magnum spec is 9.58, 360 LA spec is 9.59.... .010 difference.... I've decked plenty of blocks .020-.030 so .010 is of no concern.... So I'm here to ask if there's something else I need to be aware of, what's gonna bite me on the butt?

Edit, yeah, I know about the oil passage, got that covered..

I appreciate everyone's input...
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Check in with GTXJOHN over in Boulder. He runs Stock and Super Stock. Very hip on stuff.
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