915 heads in a 69 GTX

[ericisback]

Is it possible for a 69 440 GTX to have 915 heads, from the factory? The fender tag shows a “915” engine code.

 

[Outsider]

No, not a '67. Fender tag does not refer to head casting number.

 

[Jerry Hall]

Not from the factory, but it was a great performance upgrade in the day, as long as you didn't go with to much lift on your cam. It raises your compression almost a full point, like from 10 to 11 to 1.

 

[ericisback]

This thread seems to indicate that it was possible, but I thought 915’s were only available in 67:

Help With Fender Tag Decoding

But others in the thread said 915’s in 67 only. Wasn’t sure.

 

[Jerry Hall]

915 heads are 1967 only. There were two versions. Standard had 1.60 exhaust valves and HP had 1.74 exhaust valves. Read my previous post.

 

[ericisback]

915 heads are 1967 only. There were two versions. Standard had 1.60 exhaust valves and HP had 1.74 exhaust valves. Read my previous post.

Thanks.

 

[MarkLevi]

The fender tag shows a “915” engine code.

Presumably a Lynch Road car then (RS2xL9A) and "915" is top-left 2nd line. (Other plants don't code this to the tag in this manner) That is the code for the engine assembly, not its heads. The last three digits of the part code number for your engine.

915 - 440 4BBL, manual transmission, heater, 375hp, Orange 1969

Next three are your axle assembly, and the three after that are the transmission.

*Edit to add your carb info since I had it handy: Carter AVS 4617 part# 2946 578 (78 appears on the broadcast in the "Carb" slot)*

 

[69Coronetrt]

Mark Levi's post is entirely correct.

In this instance the 915 is not the last three digits of a part number. The 915 indicates an entire assembly comprised of different parts built for a specific application (for an A/B/C body, HP or not, manual or automatic transmission, with or without a/c, etc). It is an internal production number assigned to the engine when assembled. It is not something you go to the parts counter and order.

 

[ericisback]

Presumably a Lynch Road car then (RS2xL9A) and "915" is top-left 2nd line. (Other plants don't code this to the tag in this manner) That is the code for the engine assembly, not its heads. The last three digits of the part number for your engine.

915 - 440 4BBL, manual transmission, heater, 375hp, Orange 1969

Next three are your transmission, and the three after that are the axle.

Presumably a Lynch Road car then (RS2xL9A) and "915" is top-left 2nd line. (Other plants don't code this to the tag in this manner) That is the code for the engine assembly, not its heads. The last three digits of the part number for your engine.

915 - 440 4BBL, manual transmission, heater, 375hp, Orange 1969

Next three are your axle assembly, and the three after that are the transmission.

*Edit to add your carb info since I had it handy: Carter AVS 4617 part# 2946 578 (78 appears on the broadcast in the "Carb" slot)*

Thanks!!!

 

[66Satellite47]

Post #5 makes a very good point regarding the 915 head castings. There are two versions, there low perf with the 1.60 exhaust valve and the HP with the 1.74 exhaust. It's possible some late '66 cars got some low perf 915's or maybe even some very early '68's. The '69 motors were well into the period when the 906 heads were used. One of my '68 440's was an April motor and had 906's.
Reading fender tags or broadcast sheets takes an awful lot of experience and access to factory info.
The closed chamber HP 915 is worth nearly a 1 point increase in CR compared to a 906 head. Pull the valve covers and look at the casting numbers on the head to see what they are.

 

[Jerry Hall]

Post #5 makes a very good point regarding the 915 head castings. There are two versions, there low perf with the 1.60 exhaust valve and the HP with the 1.74 exhaust. It's possible some late '66 cars got some low perf 915's or maybe even some very early '68's. The '69 motors were well into the period when the 906 heads were used. One of my '68 440's was an April motor and had 906's.
Reading fender tags or broadcast sheets takes an awful lot of experience and access to factory info.
The closed chamber HP 915 is worth nearly a 1 point increase in CR compared to a 906 head. Pull the valve covers and look at the casting numbers on the head to see what they are.

My post #3 and #5. Thanks

 

[MarkLevi]

In this instance the 915 is not the last three digits of a part number.

Yes - agreed. That was errant on my part as to coding convention as we know it.

M

 

[Dave6T4]

I pulled an engine down years ago, and it had the small valve 915 on one side and the regular small chamber 383 head (516?) on the other side. I thought I had hit the jackpot with the 915 head until I saw it had small exhaust valves. This was the first I had learned of this abberation.

 

[Cheapsunglasses]

Not from the factory, but it was a great performance upgrade in the day, as long as you didn't go with to much lift on your cam. It raises your compression almost a full point, like from 10 to 11 to 1.

That’s what I always heard, throw the direct connection catalog and 915 heads on your car and presto, race car!

 

[65wgn440]

I pulled an engine down years ago, and it had the small valve 915 on one side and the regular small chamber 383 head (516?) on the other side. I thought I had hit the jackpot with the 915 head until I saw it had small exhaust valves. This was the first I had learned of this abberation.

Why would anyone care about stock exhaust valve size ? Who in the heck would run these heads without going to (at least) 2.14" and 1.81" valves ?? Never understood everyone asking if it's an "HP" head or not.

 

[66Satellite47]

As a drag racer, I did just as you said. I did whatever level of porting I wanted and cut them for 2.14/1.81" valves. But that's a drag racer approach. If you are a resto person you look differently. As I understand it the small valve version was most common on the C body cars.

 

[440 4 speed]

As a drag racer, I did just as you said. I did whatever level of porting I wanted and cut them for 2.14/1.81" valves. But that's a drag racer approach. If you are a resto person you look differently. As I understand it the small valve version was most common on the C body cars.

All factory 67 b bodies with 440’s had big valves. Most C bodies had small valves except 440 Super Commandos, 440 Magnums and 440 TNT’s.

 

[1968rt]

Heres what I know about 67 closed chambered heads. factory HP castings have a large HP stamped into the flat part that accessories bolt to. Small valve 915s do not. Over the counter 915 heads have a 440-X or a 440 HP stamped under the manifold runner and no cast in letter. Also large valve 915 heads normally have an "L" cast underneath, small valve 915s have a "K" and over the counter heads have no cast in letter. See pictures Coronet R/T Headstamp

 

[66Satellite47]

I'm not sure how the foundry would know what the application would ultimately be, so how would they know which letter to cast?? My observation is that there was no difference between low & HP other than the valve size they were cut for. I have had a number of sets of each.

 

[RemCharger]

The foundry just casts parts. The factory uses whatever castings they need to make the run of assemblies they want. There were 2 versions of 440 chyrsler offered, an L code, and a K code. Was it coincidental? I'm doubtful.
I believe the difference was the material in the exhaust throat. So they didn't have to bore out huge amounts of material to put the big valves in. I'll throw in my own speculation, that if they were in a pinch for L heads, they "could" have pulled k heads off the shelf and done the extra machining to keep up with demand. They really didn't know how many would sell, and as an example, they only produced 660 for the 67 charger. Of course there were more with the GTX, RT etc.