69hemibeep
Sponge Bob Square Wheels
Chrysler used alot of nickel in the castings making them harder. Its most likely your ok unless it was used like a pickup, run hot with a load!
Two Steps Back....
- Thread starter dobie
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moparchris
Well-Known Member
I have had alot of experience with the 360 which is a thin wall casting like the 440. I have safely bored my motors to .060 with no issues what-so-ever and have used nitrous and turbos to produce anywhere from 600 to 900 hp with no cylinder or piston/ ring seal issues. Now with that said, find a good machine shop and trust them. Always sonic check the blocks before boring so as to not do things twice. I have had stock 440 with .060 before as well but I havent put the hurt to 'em like I have with the small blocks. I have also had the xe274 comp cam in a 68 runner with an auto and it ran 13.77 at 101mph, considering its 8.5 compression thats not too bad. It was stock with performer rpm air gap and 750 cfm holley and 3:91s. IMHO I would not spend any money on the heads if you use that cam and have low compression. The 906's will work much better on your 383 than on your 440 because you only have to move enough air to feed a 383. Either way you sound like you have a good package coming together and your car should run well. 
mcmopar
Well-Known Member
More than likely he did not have them put in. The only way to tell is to take the heads off the engine, remove the valves and look at the valve seats. If he had them replaced they would have had to be pressed in and then machined so as to seat the valves. You would see a distinctly different color between the head and the seats.
Depending on how many miles are on the engine its hard to say if/how much damage would have been done to the valve seats. There is more than likely a bit if the engine was run over a long period of time with unleaded fuel. I would not be too concerned about it as long as the engine runs well. You could do a compression test to check and see that all the cylinders have nearly the same pressure. If some are way off it is possible the seats have sunk and your valve to seat seal has been compromised.
Since you are running 110 leaded you won't have any more concerns about valve seat wear but if you want to save some money on fuel go to http://www.maxlead2000.com/ and check out a product called Max Lead 2000. You can add this to your fuel and it will protect your valve seats because it is real tetraethyl lead which was added to the fuel of yesteryear. I used to run it in mine until I got my timing figured out, even though I have the hardened valve seats. Tetraethyl lead also stabilizes your fuel and bumps up the octane to prevent pinging and detonation (which was my problem due to my domed pistons resulting in higher than stock compression). It works very well. I experimented with the amount to add, finally settling on 200 ml per tankful (about 6 oz.) Check out the website to get the lowdown on it.
It may be $45 per gallon but at 8 oz. per tankful it will last you 16 tankfuls. If you only need 6 oz. per tankful then it will last 21.33 tankfuls. At 10 mpg you'll have enough to go 3200-4266 miles or about 1 year's worth of driving if you only drive the car now and then. Doing the math, 8 oz. of Max. Lead 2000 will add $2.81 to the cost of a tank of gas while 6 oz. will add $2.11. If you are concerned about valve seat recession or are having problems with pinging, run-on, or detonation then this may be the answer you've been looking for.
Depending on how many miles are on the engine its hard to say if/how much damage would have been done to the valve seats. There is more than likely a bit if the engine was run over a long period of time with unleaded fuel. I would not be too concerned about it as long as the engine runs well. You could do a compression test to check and see that all the cylinders have nearly the same pressure. If some are way off it is possible the seats have sunk and your valve to seat seal has been compromised.
Since you are running 110 leaded you won't have any more concerns about valve seat wear but if you want to save some money on fuel go to http://www.maxlead2000.com/ and check out a product called Max Lead 2000. You can add this to your fuel and it will protect your valve seats because it is real tetraethyl lead which was added to the fuel of yesteryear. I used to run it in mine until I got my timing figured out, even though I have the hardened valve seats. Tetraethyl lead also stabilizes your fuel and bumps up the octane to prevent pinging and detonation (which was my problem due to my domed pistons resulting in higher than stock compression). It works very well. I experimented with the amount to add, finally settling on 200 ml per tankful (about 6 oz.) Check out the website to get the lowdown on it.
It may be $45 per gallon but at 8 oz. per tankful it will last you 16 tankfuls. If you only need 6 oz. per tankful then it will last 21.33 tankfuls. At 10 mpg you'll have enough to go 3200-4266 miles or about 1 year's worth of driving if you only drive the car now and then. Doing the math, 8 oz. of Max. Lead 2000 will add $2.81 to the cost of a tank of gas while 6 oz. will add $2.11. If you are concerned about valve seat recession or are having problems with pinging, run-on, or detonation then this may be the answer you've been looking for.
mjoyner408
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i sis a 5 gal of 110 and 5 gal of 93 with an additive from autozone. it was in a grey bottle but i do not remember the name. it runs like a chetta with it's tail on fire. hell it runs good enough for me not to worry about it untill the drivetrain comes out. some how i doubt he had that done. thanks for the reply!
mcmopar
Well-Known Member
When you take out the drivetrain and are ready to go through the engine look at having the hardened seats installed in your 906 heads or go with a set of 452 heads. Installing the hardened seats is the way to go if you are looking to maintain originality but be aware that in very rare instances the seats can come out because they are pressed into place with a hydraulic press. It is extremely rare for them to drop out but it can happen. I went with the 452's simply because a buddy had an untouched set and he offered them to me.
Of course, if you are not interested in originality you can always grab a set of aluminum Edelbrock heads. They have the hardened seats, too.
Of course, if you are not interested in originality you can always grab a set of aluminum Edelbrock heads. They have the hardened seats, too.
mjoyner408
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i will prolly keep the 906 for the originality but i have a set of 452's also. it depends on how i feel at the time on what i do. thanks for the info tho!
mcmopar
Well-Known Member
Once the valve covers are on no one can ever tell until you yank them off! :jester:
Plymouthfan
Well-Known Member
I have 346's....
mcmopar
Well-Known Member
I had a set of 346's on my '71 Charger. Some of those heads (late year castings) came through with hardened seats as well.
toms69rr
Well-Known Member
Mine is an early 69 build
Motor is a 68 383 with 250 heads. Number matching car
Did some research found out they were early 906'S
When I had the heads redone,valve guides ect. I had harden seats put in
The price wasn't bad, they only charge $8.00 seat
$128.00 total
Motor is a 68 383 with 250 heads. Number matching car
Did some research found out they were early 906'S
When I had the heads redone,valve guides ect. I had harden seats put in
The price wasn't bad, they only charge $8.00 seat
$128.00 total