I thought only 915s were closed chamber?

[slimt]

Well....probably due to long oil changes more than low mileage. Most that didn't drive much didn't do oil changes thinking that it didn't need it. Also back then, oil sucked imo so unless you know what the maintenance schedule was, it's hard to attribute the root cause of worn guides. Heck, worn guides could be from lousy factory machining. IE, they were loose to start with....

ya. I guess. I was told that driving to a store and back home and not letting the oil flow to keep the guides lubricated could cause that. To be honest I dont know. Its does not burn through acceleration. Just on decel. Alot can happen over a 40 year or more period. I got all the paper work from back when new. But nothing over the past say 15 years. Well get it done and continue. .

 

[R413]

All BB mopars 1958-1967 Had closed chamber heads. There are many different part numbers. And things like 4 bolt valve covers, no rocker stands cast into the head, no bolt holes in the ends of the heads 1958-1960, and those oddball disc freeze plugs 1958-1962.

516 heads get a bad rap. They are not bad at all and are really fine for street car. You can spend a lot on porting and they work for racing also.

915 heads came on the 1967 model year only.

 

[69 Sleeper Bee]

516 heads are closed chamber but with smaller 1.60 exhaust valve and they have smaller more restrictive ports as far as air flow. Still a good head for it’s time.
You can put bigger 1.74 exhaust valve in but they aren’t conducive to good flow like newer heads.
915 heads were 1 year only closed chamber but they came with 1.60 or 1.74 exhaust valves depending on application.
915 heads have much bigger exhaust ports and the shape of the exhaust chamber makes for much better flow.
915 HP heads are the same with 1.74 exhaust valve except they came with a stiffer spring ( I think 120# HP & 90# standard ) because they were for the new 440 engine Chrysler was promoting with a hotter cam.
Bottom line is a new set of aluminum heads would out perform either of these heads.
Are you looking to be all original or not really depends on you.
No right or wrong answer as it is your build.

 

[1968rt]

The larger valve 915s had the throat opened up from the factory to accept the 1.74 Exhaust, that's the main difference. Small valve castings were cast with a "K" and large valves with an "L". 915s were also offered over the counter. I'm not sure how long they were offered. I put an NOS pair on my motor with stainless valves and a little porting. The guy I got them from was a big racer in the early 70s. The over the counter heads had no letter cast into them.

 

[wagonman]

Had a set of 915s off a 67 C- body small valves. Sold them at the Portland swap meet about 4 years ago. $150 IIRC. Was not going to put about a grand in them with larger valves and the machine work.

 

[69 Sleeper Bee]

Here is a 915 HP head with the “L” casting and 1.74 exhaust valve
In the back on the 2nd photo is the 516 head with smaller 1.60 exhaust valve.
Also notice the valve spring size of the 915’s and exhaust port difference
Both closed chamber heads.

 

[R413]

The heads above had had a lot of work on the exhaust ports. You can see straight in at the entire exhaust valve. They don’t look anything like that in stock form.

 

[patrick66]

A complete list of BB heads, taken from a Moparts list. All in BOLD are closed chambered heads, and I do in no way, certify its authenticity as being 100% correct...or correct at all!:

Big Block Cylinder Head Part #'s
Casting#

Part#

Engine Chamber In Ex
1737637
1944705

2128533 58-59 361 Closed 1.94 1.60
1737637 2448752 60 361/383 Closed 1.94 1.60
2206324
2206924 2128589 61-62 361/383/413 Closed 2.08 1.60
2402286 2402358 62 413 Max Wedge Closed 2.08 1.88
2463209 2406754 63 426 Max Wedge Closed 2.08 1.88
2463200 2448752 63 361/383/413 Closed 2.08 1.60
2406518 2406736 64 426 Max Wedge Closed 2.08 1.88
2406516 2406732 64-67 361/383 Closed 2.08 1.60
2406158 2806019 67 440 Closed 2.08 1.60
2780915 2800762 67 440 HP Closed 2.08 1.74
2843906 2843904 68-70 383/440 Open 2.08 1.74
2951250 2843904 68 440 Open 2.08 1.74
3462346 3462344 71-72 383/400/440 Open 2.08 1.74
3462346 3671640 73 400/440 Open 2.08 1.74
3751213
3751218 73 400/440 Motor Home Open 2.08 1.74
3769902
3769910 74 400/440 Open 2.08 1.74
3769975
3769954 75 400/440 Open 2.08 1.74
4006452
3769954 76-78 400/440 Open 2.08 1.74

Pre-'64 heads are easy to identify because they use only 4 valve cover bolts.

 

[polyjohn]

Great thread on a very rare Mopar head!

I have ported all the heads from the 'lowly' 516 to the 452's and the awesome Max-Wedge.
440/383 Intake ports are all very similar up to 1970, but the problem lies in the exhaust area's.
The worst ex-port is the 516 and the best is well, all the others...
None have the flow capabilities of the Max wedge, but are good street heads.

If you look inside the exhaust-ports there is a casting area that projects into the flow path.
This is most noticeable with the 516 and was corrected in the 915 casting onwards.
Yes a 1.74 is very doable in the 516, but a 915 will take a 1.81 comfortably...

 

[polyjohn]

Hard to find good pics of Max Wedge heads?
Anyways they have nice ex ports as you would imagine...

No lumpy bits in the flow-path...

 

[PRHeads]

Through the years I’m sure there were plenty of 516 heads that went to the scrap yard because of the bad press about how crappy they are for a performance build.
The fact is, for mild 383’s up to around 400hp, or 440’s up to around 450hp........ swapping them for equally prepared later heads(906/346/902/452)
won’t make very much difference in power.
And it’s easier to end up with decent quench using the closed chamber 516, making the build more pump gas friendly.

These days, It’s rarely going to be the case where it would make sense to spend the $$$ to completely go though some worn out factory heads(any castings) instead of just buy aftermarket replacements.
But there are some builds where reusing the factory heads is a viable/desireable option.

 

[66Satellite47]

Guess I mostly agree with PRH on this. I ported a number of the 516 heads for customers. The exhaust ports are very little smaller than the 906. The 516 are a good head for a moderate build. Just a a little porting on the intake is good for a moderate lift cam. Opening the exhaust port a bit and using the 1.74 valve gives real good performance for a moderate build. A little grinding makes a 516 much better than a stock 906.
I think 915's started sometime in '66 with the small exhaust valves. I've had a couple sets of the small valve 915's. Which I put in 2.14/1.81's .
The '67 HP 915's in the GTX's & HP Coronets are fairly rare. The small valve versions were fairly common back in the day when I was collecting iron heads.