'516' vs. '915' small valve heads

[copper67sat]

A little background...I bought a 'G-code' (383 2bbl) 67 Satellite convertible in the early '90's with about 90k miles on it. Previous owner (#2) only had it a short time and was over his head doing a brake swap. I got it running/driving and kept it for a few years as a long-term project before deciding it needed more metal work than I wanted to deal with so I stripped and junked the shell. I broke the 383 down to a short block and pieces to make it easier to move around and never inspected it any further.

I recently pulled out the heads to check them for another project and was surprised to see they are 915 castings rather than the 516s that I was expecting. No HP stamping and 1.60" exhaust valves which I think would typically make them Chrysler/Imperial 440 heads.

I don't know the full history of the car, but I had no reason to think that this was anything other than a factory build that had never been apart - original single snorkel air cleaner, factory carb, intake, log manifolds with no gaskets, etc. Now my questions...

How common or uncommon is it to find these heads on a 383 from the factory?

Given they are different castings, I am assuming there must be differences between 915s and the more typical 516s. Anyone know what they are, if any?

Seems like they would be good heads to put in the bigger exhaust valves and use on a mild street 383 build.

Thanks in advance for any information.

 

[pnora]

They were swapped out at some time. Are you sure its a 383 engine?

 

[copper67sat]

They were swapped out at some time. Are you sure its a 383 engine?

Good question. I don't remember if I ever checked before, just assumed, so I went out to the garage.
C383 with a March build date that goes with the April SPD of the car.

 

[Jerry Hall]

Swap to 1.74 exhaust valves and they are the same as a 67 440 HP head.

 

[moparedtn]

2708915 – 1967 440 B/RB-series big-block, 2.08/1.74 valves, 73.5cc, HP

2780915 – 1967, 440 B/RB-series big-block, 2.08/1.74 valves, HP

2406516 – 1964-1967, 361/383 B/RB-series big-block, 2.08/1.60 valves

A Guide To Mopar V8 Cylinder Head And Block Casting Numbers

 

[Jerry Hall]

Do you have the ability to check how far in the hole the pistons are in that 383? To answer your question I have also seen 915 small valve heads on two 67 383's. I have no idea if they were original to those engines. I personally put 915 HP heads on the 67 Satellite that I bought new as a performance upgrade in 1969. It was well publicized in the day as was swapping to the 440 4bbl carburetor. I'm sure I'm not the only one.

 

[Curiousyellow71]

915 shared the port shape with the later 906
but with a closed combustion chamber. They certainly respond better to porting and bigger valves then the 516s. There is not much short side radius on the intakes on the 516 and the exhaust is pretty restrictive.

 

[Dutchrebuild]

Most likely... Chrysler started using up the 915 casting heads towards the end of the model year

 

[copper67sat]

The block is stock bore. I'll try to check piston depth this weekend. The block is not on a stand so it might be difficult to get a piston to exactly TDC, but I'll give it a try.

If these are not from the factory, I don't understand why someone would go to the trouble of swapping on these heads and yet leave everything else stock, including log manifolds, single exhaust and 2.94 open rear end. Nothing on this car indicated any kind of performance upgrades. Only other reasonable rationale for a swap is that the original heads were somehow damaged and these were the replacements. It seems more plausible to me that this engine left the factory with these heads.

 

[copper67sat]

Most likely... Chrysler started using up the 915 casting heads towards the end of the model year

That makes sense since they were switching to the 906 heads in 68.

 

[pnora]

That makes sense since they were switching to the 906 heads in 68.

Find the casting dates. That could help make some sense. Burt valves were not uncommon back in the day. So someone could of swapped a pair of used heads or reman heads. Plus you know no history from the first 23 to 28 years of the cars life. May not even be the original engine.

 

[pnora]

Most likely... Chrysler started using up the 915 casting heads towards the end of the model year

What proof do you have on that statement?

 

[Dutchrebuild]

I have no proof...it simply makes sense that if Chrysler had a surplus of 915s towards the end of the 67 model year they would use them up. I've had a few low performance 67 440s and 1 late 67 383 that had 1.60" exhaust valve 915s from the factory, and without the HP stamps on them

 

[R413]

I have seen 915's on 67 383 engines. Uncommon but not out of the question. Many of my cohorts in mopars have seen this also. I'm talking in the 80's when these cars were not worn out and rebuilt 3 times.


Pretty easy to spot most head change jobs, plug wire looms in wrong place or missing, intake insulation gone, head gaskets without 7 digit Chrysler number, etc.

 

[copper67sat]

Head casting dates - 10/31 & 12/05/66

Block casting date - 2/8/67. Build date posted above - 3/14

SPD - 4/05/67

Can't prove anything on a 67 with no VIN stampings, but all the dates make sense for an original engine and I've seen enough oddities to avoid saying 'never' when it comes to Mopar. Overall, provenance doesn't really matter though since the car is long gone and was a low option, nothing special car a anyway. Only makes for interesting discussion/debate.

Mostly I was intrigued, and happy, about the unexpected find. Now I can decide between the 915s and some 906s a friend gave me.

 

[1968rt]

915s are approx 79cc from the factory. 73.5 is the NHRA blueprint spec

 

[gtxrt]

l bought a 1967 imperial engine with 915 heads and 1.60 exhaust valve. did a nice valve job and better springs car runs great plenty of low end power the 1.6 helps the low end car still pulls strong to 5500 rpms