Identifying 502's
#5
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Joined: May 2009
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From: Chicago, IL; Onekama, MI
92's I believe are all Mark IV blocks. I know mine are Mark IV, mine are also bowtie blocks. Some were standard 4 bolt blocks and some were bowtie. From what I've read when Merc first started using the 502, GM ran out of standard blocks so to keep production going GM would use bowtie blocks.
#7
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92's I believe are all Mark IV blocks. I know mine are Mark IV, mine are also bowtie blocks. Some were standard 4 bolt blocks and some were bowtie. From what I've read when Merc first started using the 502, GM ran out of standard blocks so to keep production going GM would use bowtie blocks.
#9
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Joined: Jul 2004
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From: chicago
I dont think there ever was a MARK IV 502 NON bowtie block. Production 502 blocks, started as GEN V. I think mercury marine was one of GM's biggest customers with a demand for a 502ci block, and they went into the mass production process of them. The bowtie mark IV's were used from around 1990-1992. 93-95, was mostly gen v production blocks.
The Mark IV bowtie, is a much better block than the GEN V production block. If it has a fuel pump boss, and a bowtie emblem cast into the side of the block, its a Mark IV bowtie. No fuel pump boss, prob a GEN V production block.
IS your fuel pump on the block, or on the sea pump?
The Mark IV bowtie, is a much better block than the GEN V production block. If it has a fuel pump boss, and a bowtie emblem cast into the side of the block, its a Mark IV bowtie. No fuel pump boss, prob a GEN V production block.
IS your fuel pump on the block, or on the sea pump?
#10
If memory serves, the mk iv bow tie blocks were available as standard or Siamese bore. The Siamese could take a larger bore. The block id number will also identify it.
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Straight bottoms and flat decks
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