1970 RS/SS 396 PARTS NUMBERS

Discussion in '1970 - 1973 Specific' started by rs/ssmike, Jan 20, 2018.

  1. Gary S

    Gary S Administrator Lifetime Gold Member

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    Apr 14, 1999
    Bismarck, North Dakota
    I have two different books that show these water pump numbers.
    3931065 for both L34 and L78 with a change to 3969811 for late production for both engines in 1970.

    Both books also show Z28 using 3953692 water pump the same as all small block engines for 1970.
     
  2. rs/ssmike

    rs/ssmike New Member

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    Jan 20, 2018
    Sonora, CA
    The Camaro Research Group shows 3969811 being used on some 69 big blocks. It sounds like a date code correct 3969811 will be the ticket for a motor built 1/7/70.
     
  3. john Gialanella

    john Gialanella Veteran Member

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    Oct 15, 2008
    Bloomfield N.J.
    Scott is correct. 6440727 is for L-34 and LS6 engines which both had return lines, but L-34 had Rochester Carb & LS6 had Holley carb. I was told the L-78 also used the same Fuel pump. I owned a 1970 L-78 Camaro and that is the one I had on it. My present SS 396 L-34 has 6440727 fuel pump.
    John.
     
  4. shad_van

    shad_van Veteran Member

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    Jun 15, 2012
    las vegas, NV
    my 71 SS396 LS3 car also has the 6440727 pump. the L78 and LS6 did not use a fuel return line, were the L34 and LS3 cars have a fuel filters that connect to a 1/4 fuel return line that runs back toward the pump inlet and connect to the tank return lines on the frame.
     
  5. john Gialanella

    john Gialanella Veteran Member

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    Oct 15, 2008
    Bloomfield N.J.
    If you look in the 1970 Camaro assembly manual under LS6 they have several pages and one page shows the LS6 engine with return line. Are you saying that is a mistake in the manual.
     
  6. shad_van

    shad_van Veteran Member

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    Jun 15, 2012
    las vegas, NV
    John, I don't have a 1970 Camaro assembly manual to look at the LS6 option. I have only ever seen couple real L78 cars and I have only seen pictures of that Smokey Yunick LS6 pilot car, and I only have my 1971 assembly manual to go by and it does show a return line on the LS3 cars, in UPC LS3 Sheet 6M-3. too my understanding, the L34 was similar to the LS3 with the exception of the fuel filter and mounting brackets. all the L78 cars I have seen used the 40727 fuel pump and did not use a return line. I could be wrong here, I am by no means an expert, only having seen a couple real L78's. but I would love to see a scan of the assembly manual page if you would not mind post it.

    As for My thoughts on the LS6 Camaro, I know there was a production change on the Chevelle LS6, and to my knowledge they started with the 40727 pump, and then switched to the 40768 pump in early January 1970. the 768 pump did have a return line and was higher volume than the 727 pump. since the 70 Camaro did not go in to production until January, I suspect that the LS6 Camaro would have used the 768 pump and had a return line, just like your assembly manual shows. I would love to see what part number is listed for the fuel pump in the manual as well.
     
  7. Dave Nelson

    Dave Nelson Veteran Member Gold Member

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    Dec 19, 2003
    Vineland N.J USA
    The 70 manual shows the LS6 using part # fuel pump 6440727 along with fuel filter 5651462 like the L34 with return line to tank.
     
  8. john Gialanella

    john Gialanella Veteran Member

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    Oct 15, 2008
    Bloomfield N.J.
    With the LS6 having return line in 1970 assembly manual, maybe because it was dropped, and only put in Chevelle's maybe they decided not to have return line for the LS6 Chevelle's.
     
  9. 70 SS/L78

    70 SS/L78 Veteran Member Lifetime Gold Member

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    May 5, 2005
    Rockford, MN
    The LS6 in the 70 Chevelle used a different fuel pump than the L78 or the L34. It had a longer canister on the bottom with a return line. I'm not 100% sure that all LS6 motors used the pump shown below but I know this style was used.

    LS6 fuel pump.jpg
     

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