Is this a LS-6?

Discussion in 'Blocks' started by chromebumpers, Sep 15, 2018 at 9:33 PM.

  1. chromebumpers

    chromebumpers solid fixture here in the forum Staff Member

    What month is L-5-70 for a Chevy block and it’s a casting 3963512.

    Why would the cap fasteners be studs instead of bolts?

    7B131A38-4C98-4031-84A4-8B53C4549ECC.jpeg B49B26B4-B2BE-4E06-A89C-3EB8D18E8D95.jpeg C739ECC1-C019-41B1-B171-0F01D5F6F1D1.jpeg
     
  2. chromebumpers

    chromebumpers solid fixture here in the forum Staff Member

    It has a bore of 4.310
     
  3. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

    so its already at least .060 over bore and probably can,t safely be bored much larger,
    certainly not without a sonic bore wall thickness check,
    and the main cap studs strongly suggests the block may have been previously line honed.
    the surface rust may not be a big issue but its certainly something ,that should be removed,
    lifter bores and cam tunnel should be checked for cracks.
     
  4. chromebumpers

    chromebumpers solid fixture here in the forum Staff Member

    A couple things to mention.
    Upon reading some links it was suggested that a Corvette 454 would have been a 2 bolt main while a 70 Chevelle block has 4 bolt mains on the 454’s point towards a LS-6.
    I caught this block while buying a 1970 454 Quadrajet and manifold (not connected to the block in question). The seller has this block and wants a lot of money for it, likely too much money.
     
  5. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

  6. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

  7. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    Likely a Past Race Engine Richard.
    It may Ok.
    Not rusted that bad from what see.

    Restoration value.
     
  8. chromebumpers

    chromebumpers solid fixture here in the forum Staff Member

    I totally forgot to look for a vin stamp.
    This would be the most interest to me if It had a vin derivative, then I could look for the car that it was from or be seen by the car owner looking to have a matching numbers car.
    Not worth the $2K asking price!
     
  9. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    You know the Chevrolet Market better than me Richard.
    If it was a Late 1961 to Jan 1963 SD421 Block the Value would be $10,000-20,000.

    1970 RAIV $5,000 to 10,000.

    SD455 $10000- $15000.
     
  10. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    1969 RAV Block value Be $15-20k.
     
  11. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    Vin number would only matter on SD455.
    to get $300k-500k Auction value SD455 Trans Am.
     
  12. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    Chevy Guys Go Nuts for Yenkos.
     
  13. chromebumpers

    chromebumpers solid fixture here in the forum Staff Member

    It may not have a VIN stamp, otherwise it would have been mentioned by the seller.

    It’s very difficult to find any good parts worth investing in. Everything is priced for a very ambitious future.
     
  14. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    Kinda feel the same way.
    Prices for typical 389,400, & 455 have skyrocketed.
    I don't have a good explanation.
    Cores supply may be drying up .
     
  15. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    LS6 Is Legendary.
    How many left I do not know.
     
  16. chromebumpers

    chromebumpers solid fixture here in the forum Staff Member

    Both Barrett Jackson and Mecum - among many other specialty car auctions won’t take any more consignments claiming to be a first gen LS-6 as there are already more around than what GM made - unless the car is from a known collector and has verifiable provenance. This and other conditions are spelled out on their contracts.
     
  17. chromebumpers

    chromebumpers solid fixture here in the forum Staff Member

    The same thing has been going on with 1969 COPO Camaro. Reggie Jackson has traded and collected almost 2 dozen COPO Camaros and even he said it’s rare to have a COPO that has its original motor.
     
  18. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    It's Rare for Top Pontiac Factory Race Cars to have original motors.
    Most have over the counter dealership motors.
    SR Service replacement motors.

    If I had the money I would buy that LS6 Block.
    Try for $1500.
    Get the Crankshaft and Square port LS6 Heads if possible for extra on top of $1500.
     
  19. chromebumpers

    chromebumpers solid fixture here in the forum Staff Member

    I have a pair of Winter heads traded back in ‘09. They didn’t cost me much and I been wanting to get them cleaned and checked. I guess I’ll get those heads configured once I know the final application
     

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