I knew I had another set of these

Mixed-up XP · Apr 17, 2021

Found these stashed in a box with some other parts. A little help here please...I guess I never paid attention to it or just never give it any thought. What is the -1 & -2 that comes after the "915" casting? Also, is the 5 digit number below that the date of casting?

1 Wild R/T · Apr 17, 2021

-1 & -2 are indicators of the casting mold.. -1 is a fresh mold, it might be truly fresh or nearing the need to be fixed... -2 has run long enough that it was repaired Same deal, it could be truly fresh or soon to be a -3...

And the second number as you surmised is a casting date...

1968rt · Apr 17, 2021

67 closed chamber heads. the 1 & 2 are just casting mold adjustments. The heads marked K on the bottom are generally 1.60 exhaust valves and the L is 1.74. Not sure of this has been proven. I found most uncut heads to be 79-80ccs. No difference in castings. Factory HP heads have a large HP on the alternator boss holes. Over the counter heads have a small HP under the intake runner. casting dates are 216th day of 67 and 113th day of 67

Mixed-up XP · Apr 17, 2021

Good information to know. With that info, does the -2 head have any inferior qualities over the -1 or vice-versa? As far as I know, these heads came off the same engine. And can you decipher the casting date, please?

1968rt · Apr 17, 2021

As long as the valves and throats are the same they will flow the same. Make sure that they have the same cc chamber (no milling)

69 Sleeper Bee · Apr 17, 2021

1968rt said:
67 closed chamber heads. the 1 & 2 are just casting mold adjustments. The heads marked K on the bottom are generally 1.60 exhaust valves and the L is 1.74. Not sure of this has been proven. I found most uncut heads to be 79-80ccs. No difference in castings. Factory HP heads have a large HP on the alternator boss holes. Over the counter heads have a small HP under the intake runner. casting dates are 216th day of 67 and 113th day of 67

Can you tell me the casting date on this 915 head ?
Been trying to decipher this with no luck so far.
Also is this the HP stamp on the heads you are referencing ?

Jerry Hall · Apr 17, 2021

I have always read the casting date as 2 digits month, 2 digits day, and 1 digit year. @69 Sleeper Bee would be September 01, 1966

1968rt · Apr 18, 2021

Most cylinder heads use first 4 digits are days and last one is year. This doesnt work on your head, not sure why? Could be different foundary? It can only be Sept 1, 66

Jerry Hall · Apr 18, 2021

All 915 heads I have ever seen seem to read my way. I read them that way because I have seen to many that don't fit the other criteria.

1968rt · Apr 18, 2021

I checked three different websites and got three different opinions. One says its the Julian calendar, the other says month day year, and the third said day (1 of 365) then year. Could it be there are different methods? I give up!!

Jerry Hall · Apr 18, 2021

I'm only referring to 915 casting heads. I haven't dealt with enough others to say anything positive. The two I'm most familiar with 915 & 906 casting, and the 906's, I don't take that much interest in unless I'm working on a 68 - 70 car.

The 6 you see 4 are 67's one is a 72, and the other is a 2006. On the other side of the building are a few more 66-67's.

I knew I had another set of these

Mixed-up XP

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1 Wild R/T

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1968rt

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Mixed-up XP

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1968rt

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69 Sleeper Bee

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Jerry Hall

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1968rt

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1968rt

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