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SB Heads ...3947041 ... value?

51K views 15 replies 9 participants last post by  wark67 
#1 ·
I have a pair of 041 SB heads, (1.94/1.50), from my 70' Elky, ...that were replaced by S/R Torquers. I know these are desired by some ... and I'm trying to establish a range of value, before listing on ebay. They are "fixer uppers" and need rebuilding. (guides, 2 studs pulled up, etc. ... but no visible cracks) Appreciate all comments. Thanks
 
#2 ·
As a guy who rebuilt cylinder heads for 8 years, here is some advice.
Take them to an automotive machine shop and have them dissassembled, hot tanked and magnafluxed. This should cost about $20-30. When you are sure there are no cracks and they are good rebuildable cores, then list them on eBay. List the date codes.

They are worth $75-125 each, bare.
You need to factor in the shipping cost. Don't take less than 150 for the pr if they are good cores.


Nate
 
#3 · (Edited)
Nate,

When you say,"good rebuildable cores" ... does that imply ... the valve seats are not sunken and can successfully be reground as is? Or, ... is that allowing for the installation of new insert seats? Also, with your experience, how do you "read" a valve & seat to determine ... if a seat is sunken too far ..... and needs an insert? Would another solution for sunken seats, in these heads (041, 1.94/1.50), ... be to upsize and grind existing seats for 2.02/1.60 valves? Thanks again! "Learning as I go"
 
#4 ·
In order to run these heads on todays fuel, hardened exhaust seats will need to be installed.
Some (few) people may opt to have 1.600" exhaust valves installed, but it's not a long term solution.
The machine shop you have hot tank them should be able to tell you if the exhaust seats are not sunk too far to accept seats. It takes a trained eye. Some times you just have to bore the old seat for the new hardened seat and see if it cleans. Larger OD seat inserts are not really an option as the seat insert OD for the small block Chevy are already determined. I believe it is about 1.625". The OD of the seat that is recommended for the 1.600" exhaust valve heads is a bit larger than the 1.500" valves, but I never liked to put them in. You run the risk of hitting water. (cutting into a water jacket). I would just use the 1.500" valve seats and open the 45 degree out to where I wanted it on the valve face for the 1.600" valves.
The exhaust seats can be sunk quite a bit before the head is scrapped. You see, the head of the 1.500" valve measures 1.500", thus it cannot make a hole when sinking the seat much bigger than 1.500". Maybe out to 1.550 or so ??. And the inserts measure 1.625" OD. It depends on how bad the guides are. What I'm trying to say is most heads can be saved by installing the hardened seats.
Heads with badly sunken seats tend to have cracks. You need to get them checked.

You're welcome to email me 8 pictures of the exhaust seats (1 of each), after hot tanking and I can tell you if they are in need of seats and /or if they will take a seat or not. But as I said, 99% of people will have the seats installed if they are planning on running todays fuel and keeping the car.

Nate
 
#6 ·
"service replacement part for 461's" ???
I don't know whether that is true or not. I suppose it could be.
I do know that the 3947041 heads were standard issue for L48 350's in 1969 and 1970. Same as the 3927186 heads. I would think that the 3991492 would be more likely to be a service replacement head for the 3947041 or 3927186.


Nate
 
#7 ·
I paid $75 for the pair I had about 8 years ago. Then I dumped another $1,000 into them with bigger valves, hardened seats, screw in studs and guide plates,and a full port and polish using a flow bench. They ran great on my 327. If I remember right, the 041 heads came on Truck motors. They are closer to the 186 and 492 heads than the 461. They have a 68 cc chamber and acc. holes. They are just as good as any "fuelie" if you ask me. They work good for "sleeper" motors too because most people don`t know what they are the the triangle casting mark is very similar to the later model open chamber heads. They won`t get the same money as a "fuelie" from most people unless they know about them.
 
#8 ·
They are exactly the same as the 186, and possibly the 492 as well.
I have several sets of each.

I also have a 68 327 HP truck head. It's the only one I have ever seen. Casting number 3947040 ! Try and find that number in your Chevrolet books !

As a side note, one of my 69 Chevelles still has the original L48 in it with the original 3947041 heads. They've never been off. 193K on the odometer !


Nate
 
#11 ·
They are exactly the same as the 186, and possibly the 492 as well.
I have several sets of each.

I also have a 68 327 HP truck head. It's the only one I have ever seen. Casting number 3947040 ! Try and find that number in your Chevrolet books

Nate
that numbers not hard to find:

3947040....68......327.........."Right angle" casting identifier, 64cc chambers, good HP head,
used in trucks, no accessory holes
 
#9 ·
040 heads are good too. They are the same as 041 just no acc. holes. A buddy had them on his motor and they were great performers. I would`nt build another set unless they were original heads to a original number matchin car. It`s cheaper to go aftermarket and you get a better head also.
 
#10 ·
brimac said:
I have a pair of 041 SB heads, (1.94/1.50), from my 70' Elky, ...that were replaced by S/R Torquers. I know these are desired by some ... and I'm trying to establish a range of value, before listing on ebay. They are "fixer uppers" and need rebuilding. (guides, 2 studs pulled up, etc. ... but no visible cracks) Appreciate all comments. Thanks
If you still have them, I might be interested.
 
#14 ·
And here we are 3 years later... The first set of 041 heads I got I pulled off a '71 Monte 350, they were the 041X heads and ran them on my 1975 Chevelle. I have several sets of 041 heads and I wouldn't sell them for less than $300. a set. I do have the equipment to tank, magnaflux and pressure check my heads and install hardened seats. These are great heads for the circle track guys that have head rules. I'm working up a pair for my '72 Vega just because I like the old school heads.
 
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