Goldie will get her orginal heads reconditioned.

[furious70]

I'm guessing he used a whiplash style cam?

 

[Just Carbs]

The 413 heads were in good condition and hated the local premium gas. And I was driving it a lot on the wrong gas for the seats.
The power band didn't move. The difference is it stops abruptly at the same max rpm now, the same rpm where the original 413 cam rolled off into an unusable rpm instead of dropping like a rock. But the new cam has much more torque from idle to 4k.
Still using AFB carb, points and single exhaust.

 

[Dads300]

@ just carbs, do you recall what exact cam you installed. Just curious what it is since you have positive firsthand experience.
Travis..

 

[Just Carbs]

No, I don't. I think it was a 544 lift, 230 duration, and 114-lobe separation "OR" center line, I don't remember which.
I didn't idle smooth at 600 rpm. But did idle well at 700. It came on early and shut down abruptly, at about 4800, I think. More power but when it was done it was done. Like a diesel governor.

 

[Ripinator]

@ just carbs, do you recall what exact cam you installed. Just curious what it is since you have positive firsthand experience.
Travis..

While yer waiting for Dad, I thought I would show you the cam I used. I'm running it in a 440 with 516 heads. Also, while the spec sheet for this cam says it is good with a 3.23: 1 rear end, I'm running a 2.94:1 sure grip diff. The engine is very responsive and is a joy to drive on the open road:
Xtreme Energy 218/224 Hydraulic Flat Cam for Chrysler 383-440

 

[65sporty]

I am at a bit of a quandary. The guy who is doing the work came highly recommended and has been doing it for nearly 40 years. He said I'll do what ever work you want done on the heads, but he feels new hardened valves and seats are not worth it, for the miles I will be put on my car. He said I personally wouldn't do it if I am only driving 2,000 miles a year on it, which is about my max. He charges $20 for each new hardened valve and seat so $320 total.

All that being said, hardened exhaust seats was mentioned by 65sporty. Can I just use the hardened seats and valves on the exhaust and not the intake valves? Also if I go ahead and the enlarged exhaust valves like dematt suggested, this is just helping the performance of the engine without having to do any other modifications?

More information, I currently have 77,000 original miles on Goldie. I would love to say I will be driving her for another 30 years, so probably between 45,000 and 60,000 miles. I don't mind spending the money now because I will never sell her.

The hardened seats are only on the exhaust

 

[69PHOENIX]

O.K.
Stupid Question Time Again.
Recently had My Mechanic (A Friend of 40 Yrs Install a New Set of Valves & Springs in a Set of 906 Heads.
While Chin Wagging with Him I asked about Reco-ing the Heads.
His Suggestion was that with the Cost Involved Nowadays it would be a better Idea to Install a Set of Aluminium (And Yes it is Spelt that way LOL) Heads.
What are You Fellas Thoughts on This.
Regards Tony.M

 

[LocuMob]

O.K.
Stupid Question Time Again.
Recently had My Mechanic (A Friend of 40 Yrs Install a New Set of Valves & Springs in a Set of 906 Heads.
While Chin Wagging with Him I asked about Reco-ing the Heads.
His Suggestion was that with the Cost Involved Nowadays it would be a better Idea to Install a Set of Aluminium (And Yes it is Spelt that way LOL) Heads.
What are You Fellas Thoughts on This.
Regards Tony.M

That's what I'd do, but I don't care about originality 99% of the time. Better flow, lighter weight, and depending on how much your machinist charges, close enough in price for me to pull the trigger.

 

[Mr C]

O.K.
Stupid Question Time Again.
Recently had My Mechanic (A Friend of 40 Yrs Install a New Set of Valves & Springs in a Set of 906 Heads.
While Chin Wagging with Him I asked about Reco-ing the Heads.
His Suggestion was that with the Cost Involved Nowadays it would be a better Idea to Install a Set of Aluminium (And Yes it is Spelt that way LOL) Heads.
What are You Fellas Thoughts on This.
Regards Tony.M

My thoughts: I'm an "all iron" guy so that I can avoid the problems associated with dissimilar metals. I'm reconditioning the 906s on my engine.

 

[Zymurgy]

O.K.
Stupid Question Time Again.
Recently had My Mechanic (A Friend of 40 Yrs Install a New Set of Valves & Springs in a Set of 906 Heads.
While Chin Wagging with Him I asked about Reco-ing the Heads.
His Suggestion was that with the Cost Involved Nowadays it would be a better Idea to Install a Set of Aluminium (And Yes it is Spelt that way LOL) Heads.
What are You Fellas Thoughts on This.
Regards Tony.M

I have always been a purists in just about anything I work on and most of the time it cost more to restore than to replace. I honestly didn't even consider an aluminum heads, just like when I had may radiator re-cored.

 

[tallhair]

I’ve always been under the impression that after decades of use and hammering by the valves the stock 60’s leaded seats become effectively hardened. However any valve job on hardened or unhardened seats lose all hardening regardless of how it got there. The hardening is only thousandth’s deep.

So you should definitely go with new hardened seats IMHO, unless all I understood was hogwash.

If you go with new hardened seats it would be wise to go with 1.74 valves/seats, again, MHO. The factory converted to 1.74 exhaust valves in 67 for a reason, improved flow.

I had a set of small valve 915 heads (off 2bbl 383] converted to 1.74 with the same size hardened seats, minor back cut, new valves, springs, he’d surface cleaned up, etc, etc. Was $950 approximately 7+ years ago.

 

[tallhair]

Or if not going hardened seats use lead additive for no more miles than you drive.

 

[ynst]

Thanks, the valves are burnt from running unleaded gas for the last 10 years.

....which is exactly why you want to put in the hardened seats.

I'm doing that to another pair of 906 heads for my 383 ('69 Road Runner engine) cross-ram going into a '55 DeSoto station wagon.

 

[ynst]

I’ve always been under the impression that after decades of use and hammering by the valves the stock 60’s leaded seats become effectively hardened. However any valve job on hardened or unhardened seats lose all hardening regardless of how it got there. The hardening is only thousandth’s deep.

So you should definitely go with new hardened seats IMHO, unless all I understood was hogwash.

If you go with new hardened seats it would be wise to go with 1.74 valves/seats, again, MHO. The factory converted to 1.74 exhaust valves in 67 for a reason, improved flow.

I had a set of small valve 915 heads (off 2bbl 383] converted to 1.74 with the same size hardened seats, minor back cut, new valves, springs, he’d surface cleaned up, etc, etc. Was $950 approximately 7+ years ago.

"The hardening is only thousandth’s deep."

Untrue. The hardened seat replacements are a totally different metal than the integral cast iron stock seat.

 

[ynst]

Perfect reason to upgrade to 1.74 as Matt said. I personally would not go through the trouble with hardened seats, for a couple of reasons, but everyone will have a opinion on that your decision will be the one that makes the choice.
The move to 1.74 will put the seat up high again, (always helps flow in lower lifts. The new valves will not have that stupid emission ridge on them so they will flow better at lower lifts. For as cheap as they are I would get one piece valves, helping reliability.
As for hardened seats. It is the valves that burnt not the head casting. Sure the seat is probably in bad shape, but the valve has less mass to heat up and go bad, why they take more of a beating. Your not using high valve spring pressures and a long duration cam that will hit the seat harder. Lastly a new valve job will probably outlast me, so it becomes the next generations problem.

"As for hardened seats. It is the valves that burnt not the head casting. Sure the seat is probably in bad shape, but the valve has less mass to heat up and go bad, why they take more of a beating."
The seat erodes allowing the exhaust gasses to pass through the gap. That's what burns valves. Concentrated hot spots.

 

[tallhair]

....which is exactly why you want to put in the hardened seats.

I'm doing that to another pair of 906 heads for my 383 ('69 Road Runner engine) cross-ram going into a '55 DeSoto station wagon.

I was referring to original equipment seats with many miles on them not new seats.

 

[70bigblockdodge]

....which is exactly why you want to put in the hardened seats.

I'm doing that to another pair of 906 heads for my 383 ('69 Road Runner engine) cross-ram going into a '55 DeSoto station wagon.

So how much is that costing? 906 castings aren't worth $100. 516 castings like Mike has on Goldie are worth less than that.
I think I will just stick with enlarging the valves and cutting new seats. They will outlast me.

 

[1970FuryConv]

So how much is that costing? 906 castings aren't worth $100. 516 castings like Mike has on Goldie are worth less than that.
I think I will just stick with enlarging the valves and cutting new seats. They will outlast me.

516 head castings have the small exhaust valve 1.60" versus 906 heads which have 1.74" exhaust valve.
Do you think 1.60" is enough for a 1970 383 mild cam, stock compression, stock trans, street cruiser 3.23 rear?

 

[Ripinator]

516 head castings have the small exhaust valve 1.60" versus 906 heads which have 1.74" exhaust valve.
Do you think 1.60" is enough for a 1970 383 mild cam, stock compression, stock trans, street cruiser 3.23 rear?

Yes. The 516 heads will be fine. You should select a dual pattern cam with a little more exhaust duration than intake. I'm running this setup in my 66 300 with a 440 and a 2.94 rear gear. Terrific throttle response and it cruises great.

 

[1970FuryConv]

Yes. The 516 heads will be fine. You should select a dual pattern cam with a little more exhaust duration than intake. I'm running this setup in my 66 300 with a 440 and a 2.94 rear gear. Terrific throttle response and it cruises great.

Hi Rip,
516 is closed chamber 79-80 cc. 1970 383 originally had open chamber 906 heads 88 cc.
I was also thinking about compression and wondering whether the transition to closed chamber would cause knock.
It's not my engine. I was talking to another guy. His 1970 383 has run fine with 516 heads for the first 5 or 6 runs with the car, but it didn't sound like he has tried wide open throttle. Also, with the smaller exhaust valves, I'm not sure whether that makes the problem worse with less cylinder evacuation at WOT.
Felpro head gasket may have added cc over the factory steel head gaskets, so that might have helped. I didn't ask what head gasket he used. Sounded like he had put the heads on without rebuilding them. Ben