BBC auction find

[442w30]

Hi . . . StevesParts.com on Moparts.com went to an auction and picked up these heads. This is what he says:

<span style="font-style: italic">Hello Everyone, I went to an auction today where a local Chevy racer had died a couple years ago and the family was finally ready to sell everything off. I picked up a few small items but toward the end I ended up getting a matched set of ORIGINAL ZL1 - L89 big block aluminum heads both dated late 1969 and a pair of over the counter heads both dated 1973. These are not damaged anywhere and all the rocker stands look perfect. I will be sending them out to be checked over next week and hopefully these can find their way onto a correct car. I am not really a Chevy guy but I thought these were very rare and should be on a correctly restored ZL1 or L89 car, not a race car.</span>

I think that L-89 heads are basically aluminum L-78 or L-71 heads, but the ZL-1 is a completely different animal, more like an L-88, right? In any case, I told Steve I'd post here to help determine what he has found. He says the casting number is 3946074.

So what did he pick up?

[iluv69s]

looks like he got some nice heads...the 074's are ZL-1/L-88 open chamber heads...the late 69 date hurts because they would be 70 heads most likely. Most of the ZL-s were built late February time frame I believe...although some were later.

And the L-89 heads are probably rarer I believe... both great performance GM heads. Others can chime in who are way more expert than I.

[William]

The latest production Camaro ZL1 engines I'm aware of were dated late April. May dates could be possible for the last few cars.

The L89 heads should be casting #3919842. Most will have a screw-in plug at each end; around May 1969 only one end has a plug.

[Fast67VelleN2O]

Both sets pictured are 074 heads. One set looks very ported, the other set look to have just been gasket matched but don't look milled. Remember, these heads were also used on the L88 Corvette and the LS6 Corvette in 1971. They weren't used on the L89 at all.

[442w30]

Cool . . . at the very least, he made a &quot;find&quot; whatever they are. I've given him the link to see the answers and he's very appreciative.

[ANDY M]

Of course, now that he's been schooled, the price just went up to the 427King level. [img]<<GRAEMLIN_URL>>/rolleyes.gif[/img]
Andy [img]<<GRAEMLIN_URL>>/Can-I-Have-It.gif[/img]

[442w30]

I have no idea - haven't chatted about it since I told him I'd try to find some knowledgable Chevy peeps.

[the427king]

Looks like welded up 074 exhaust port [round to D]to me.

[Day2_69Z]

Place these heads on a restored L89 where they belong, Not on a Race Car. Sounds like a bit of a reach and somewhat nieve........

Most Chevy Aluminum heads were Bought &amp; Modified for just that reason,,,,For Race Cars !

The one set as Chuck pointed out, Are D Ports, which are High end, High dollar design for all out racing of that era.

Back then, these were the Hot Ticket , Light, Easily modified and rebuildable /weldable when damaged. But, most of the raced with heads have seen a hard life. Used with roller cams, big high pressure springs, high compression and high RPM.

I'm sure the heads in front are well used.