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  1. #1
    Fuel Injected! Resin's Avatar
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    New 350 build leaking

    Hello again,

    I am relatively new to engine building. I've done plenty of work on existing engines but my experience with new builds is in development.

    I just finished putting a brand new build in my 1989 Firebird. It went from an L03 to a roller 355 w/ vortec.

    My question is, should I see any leaks? Is it normal for a new build to leak a little bit? I've got about 150 miles on it at this point.

    How hosed am I?

    1.jpg2.jpg3.jpg4.jpg

  2. #2
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    Not normal at all. Are those leaks from the LH head gasket area? What year is block? You might need to tighten a pipe plug in the LH side of blockbehind the cylinder heafd.

  3. #3
    Fuel Injected! Resin's Avatar
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    Unfortunately, each of those 4 pictures is a different corner of the block. Both left and right heads, front and back. It appears to be coming from the head to block mating surface on all four corners. The block is a marine engine from 1995 I think. I don't have the casting number off hand but I can get it. I had a machine shop go through it and bore it 30 over due to some rust from water sitting in one of the cylinders. It's a good shop and I trust their work. They decked the block and heads for me so there should not be any warpage to worry about.

  4. #4
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    It occurred to me just now that I might want to clean it off and see if it's actually leaking. A couple of weeks back, I had a heater hose burst. I suppose it's possible that some coolant ran down the corners of the block. I'm going to wipe it down and see if it comes back before doing anything drastic.

  5. #5
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    Definitely hose everything off before making any decisions.

    Do you know what was installed for a head gasket? Steel shim type or composition?

  6. #6
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    I used a composite gasket from Enginetech.

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