Value of 3946074 Aluminum heads?

[jasonL78]

What's the value of these aluminum heads came off a running motor. Trying to help a friend out with pricing and value?

Jason

[William]

Those are ZL1 & 2nd design L88 heads. If they have matching or close early-mid '69 casting dates, no signs of welded-up damage or porting they have some appeal to collectors.'69 was the only model year they were used in production. Not a big audience.

'70s casting dates are common as they were sold OTC for years.

[Ls6 Ragtop]

William,
I'm pretty sure Those heads are also production pieces on 71 LS6 Corvettes as well ( I know only 188 produced ) but still another production application for these heads.
Jason, as far as value condition makes a big difference as far as value
and I haven't bought a set in quite a while but a nice set with 69 dates should be worth a pretty good amount. I'll leave the pricing to the dealers.
Chris

[jasonL78]

Turns out they are 73-74 heads. In real good shape no visual cracks or welds all bolt holes look good.

[SuperNovaSS]

In my experience, service dated heads usually sell for $1500-$2000 if you don't mind waiting a bit for the right buyer.


Jason

[William]

After quite a search I found a pair of '70s dated 074 heads for our ZL1 project. Like these, they were in excellent condition and I had no problem using them.

I had looked at a number of heads, most showed signs of hard use: heli-coils, welds, porting. Lots of junk out there.

[SuperNovaSS]

Unmolested sets are hard to find. I wouldn't say helicoils make heads junk or show they had hard use. In the real world, helicoils are an upgrade on aluminum parts. There is a reason aftermarket aluminum heads come with helicoils already installed.


Jason

[bigsixman]

GM aluminum heads were not very good back then comparing to today's technology. William is correct in his post about common problems and I will add some more.

The valve seats were not very good and many times fell out. The rocker stands were not very strong and often times broke. The heat treat process that GM used had problems and has been corrected in modern castings.

These problems often surfaced when the cam, valve springs or rpm limits were changed out for racing purposes.

They were the best at the time, but today they should only used by people required by sanctioning rules or correctness in a restoration or a period correct street car.