My brother in law is working on a big block for a customer and the heads are as stated above, but they have a casting date of 6 20 70. My guess is they were service replacement heads for the L88 or ZL1.

Also, on the front of the head it is stamped 1476799. Maybe this is the partial VIN from the engine the heads were put on and the engine builder stamped them.

Any thoughts?

3946074....69&71...rect...OPEN...'69 427 L88, ZL1, Aluminum, 118cc chamber
'71 454 LS6, "round exhaust port"

some builders stamp numbers to track heads that are sent out..maybe???

Those heads are not common.
With a 1969 cast date, they would be made from Unobtanium, end of 69 L-88 or ZL-1 427s. You could sell the heads (if not doctored) and have a very nice European vacation.

A late JUNE casting date in 1970, all is far from lost. Actual assembly could have put them out weeks later. Makes it possible that they would be on an EARLY PRODUCTION 71 LS-6 Vette which probably began production the last two weeks of AUG (would have to verify this date). Do not consider this the final word by any means.... I'm sure that like most other things, production was in batches...so 3-4 months lead for specialty-type stuff is certainly possible. NCRS generally accepts engine blocks up to three months prior to car build date...at least last time that i checked. With (IIRC) 188 LS-6 Vettes made in 71...will leave the end off that sentence.
Maybe best to do some research on LS-6 Vettes....compare head casting dates from known examples.....

I am likely to get a set from a pal off an old race engine needing repairs, 'over the counter' heads for sure w/74 casting date. Better for high rpm engines then a street cruiser for sure.

What project are those 074s are on?

See my gallery

Production 71 LS-6 heads have a small square box stamped in the end of the head. Production L-89,L-88 Zl-1 have H C for Hi Comp stamped in the ends . If I could figure out how to load picts here I have a bunch of these I can post picts of. Real ZL-1 heads also have 2 studs in them for the extra mounting bosses on that block.

These heads are expensive to fix as the porositity of the aluminum was very bad, and they were know for dropping seats the death of many original numbered blocks.

Jim

yes, the set i am looking at did drop a seat and it did some evil damage. But nothing permanent. I'll be out for two Titanium valves too

Those heads are not common.
With a 1969 cast date, they would be made from Unobtanium, end of 69 L-88 or ZL-1 427s. You could sell the heads (if not doctored) and have a very nice European vacation.

A late JUNE casting date in 1970, all is far from lost. Actual assembly could have put them out weeks later. Makes it possible that they would be on an EARLY PRODUCTION 71 LS-6 Vette which probably began production the last two weeks of AUG (would have to verify this date). Do not consider this the final word by any means.... I'm sure that like most other things, production was in batches...so 3-4 months lead for specialty-type stuff is certainly possible. NCRS generally accepts engine blocks up to three months prior to car build date...at least last time that i checked. With (IIRC) 188 LS-6 Vettes made in 71...will leave the end off that sentence.
Maybe best to do some research on LS-6 Vettes....compare head casting dates from known examples.....

I am likely to get a set from a pal off an old race engine needing repairs, 'over the counter' heads for sure w/74 casting date. Better for high rpm engines then a street cruiser for sure.

What project are those 074s are on?

See my gallery

It is at my brother-in-laws auto shop. All I know about it so far is, a customer went to the shop with a 69 camaro with a big block and these heads were on it. The owner of the car wants some engine work done to make more power.

I have a set if 3946074 heads that I bought 6 years ago. I was going to use them on My next motor build but now that I need money to finish My car I am thinking of selling them. would these heads be correct for Z L-1/ L-88 corvetts. Dates are 2/11/69 and 2/24/69. These heads are not ported and are still original. I bought them from a guy who raced boats and heads had to be original .What are these worth? Here are some pictures. Thanks Brian

Geez Brian,
I'm sure there is some 69 ZL-1 Camaro or late 69 L-88 Vette guy out there willing to pay you a young fortune for them. PM me what you paid for them if you don't mind. I'm sure you will get your money back several fold.

I've got a set of Jan '69 dated 074 heads that I'll take a "young" fortune for. They've been welded in three spots and the exhaust ports has been opened up, but they have new valves in them. No guide plates or rocker studs.

I've got a set of Jan '69 dated 074 heads that I'll take a "young" fortune for. They've been welded in three spots and the exhaust ports has been opened up, but they have new valves in them. No guide plates or rocker studs.


I'm afraid those guys who would pay big bucks for virgin sets will pay far less for modified/repaired heads. Even heads that have mods not showing on the outside have less value.

I bought a set of these heads on e-bay a few years ago.
But I only have one good one. After I recieved them, I came to find out that someone had milled about .187 off the deck of one.:mad:
Seller dissapeared............

So I now have one good bare casting. If you hear of anybody needing one (and a paper wieght) let them know.
I'll hang on to it until someone needs it.

I could use a good paperweight! :D

I could use a good paperweight! :D

So could I but I really didn't expect a $750 one.
Needless to say, that was and is the last time I buy something without seeing it in person.

I'm afraid those guys who would pay big bucks for virgin sets will pay far less for modified/repaired heads. Even heads that have mods not showing on the outside have less value.

This is true. I don't have that much in them, so they are a nice converstaion piece. Like when standing around the garage with a few friends and a cold cooler! :bow:

I have a set if 3946074 heads that I bought 6 years ago. I was going to use them on My next motor build but now that I need money to finish My car I am thinking of selling them. would these heads be correct for Z L-1/ L-88 corvetts. Dates are 2/11/69 and 2/24/69. These heads are not ported and are still original. I bought them from a guy who raced boats and heads had to be original .What are these worth? Here are some pictures. Thanks Brian

If the little circles with the waffle like patterns are still on the bottom of the intake ports, if they dont have any welds and the studs and pushrod guides were there, you could start the bidding at $2000. Ebay them. May be able to get up to $4500 if they are really nice. :hurray: