chevy 427 ci had oil in radiator had heads redone and surfaced replaced with new head gaskets still having same problem. radiator has the 2 trans cooling lines only no oil cooling lines need some help

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    Welcome to Motor Vehicle Maintenance & Repair! What is the vehicle this is in? Is it the original setup of the engine, or is the engine a transplant? Is this a BBC or LSx engine? If BBC, does it have aluminum or cast iron heads? If BBC, which generation of engine is it? MkIV or ?? When you had the heads redone, did you flush the cooling system? Apr 14, 2020 at 13:53
  • 67 chevelle transplant for 396 i imagine. BBC cast iron heads not sure of generation late 60"s--early 70"s?? yes did fluid cooling system thanks alot for helping Apr 14, 2020 at 14:12
  • Your engine would be a MkIV BBC. I'm assuming it's a standard height block (not a tall deck or truck block). There's no coolant in the oil, correct? Apr 14, 2020 at 15:27
  • Are you sure it's motor oil and not transmission fluid? Mixed with coolant they can look similar. Any possibility of a cracked block?
    – jwh20
    Apr 14, 2020 at 16:06
  • yes std height block. no coolant in oil. tranny fluid is clear and full oil was 2 qts down when i noticed the problem when this first started a friend was driving the car and was over heating when he brought it back to me. could it be a cracked head also? or just cracked block? thanks Apr 14, 2020 at 17:04

1 Answer 1


As with the SBC, there's no oil passages running up through the heads. All oil which flows to the top end is through the pushrods. There are flow passages back down, but there's basically no pressure there. IOW: a cracked head would not cause your problem. I've been beating my head for the past while trying to remember where an oil leak could cause it to go into the water ... the only place it could be coming from is from the block ... one of the oil galleys into a water jacket. That's a guess though. You'd have to tear down the block and get it pressure tested.

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    SBC? BBC? Unexplained abbreviations aren’t helpful here. Okay to use abbreviations, Best practice is to explain all abbreviations When First Used (WFU). We all understand that abbreviations are commonly used, but can’t all aspiring mechanics and home mechanics (just learning) also benefit from visits to this site?
    – zipzit
    Apr 14, 2020 at 20:06

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