Definitely needs an instruction sheet. How many times have you purchased something only to question what the manufacturer wanted because no literature was included? Some items to include on an instruction sheet would include:

Head gasket recommendation.

Torque specs and tightening sequence.

Spark plug recommendation with the heat range.

Pushrod length if different than stock.

Head bolt recommendation with part numbers.

Any warnings – ie. “DO NOT USE ORIGINAL EQUIPMENT HEAD BOLTS!!!”, “USE ANTI-SEIZE ON SPARK PLUG THREADS BEFORE INSTALLING”, etc.

Feel free to make corrections or additions. This is just a start.

A couple years ago you and I had some contact with a possible supplier of aluminum heads.  One of the things I discussed with him was moving the combustion chamber higher on the bore.  He said that would be a gain in HP.

My Studebaker friend contracted with the same guy to make some Stude manifolds.  He paid up front money.  After a year and a lot of excuses, he asked for his money back.  Haven't heard how the deal came out, but keep this in mind if you are thinking of using that source.

John

John.  Thanks for the warning but they’ll be no up front money with where I hope this goes.  Different group.

The last two words of your post are music to my ears.  "Different group".  My Stude friend is a 73 year old retired teacher who never has anything bad to say about anybody, but flat out called that guy a liar.

John

            mY "two bobs" worth, for what it's worth,

Yes…. California

    John has found what appears to be a decent pattern and foundry in El Cajon, not in LA which is a 100 miles up the road. Edelbrock has no interest in any Y Block parts and it would be best to keep it that way.

Edit:

Possibly a chart for milling the heads .0xx/CC then a chart for deck Vs intake cuts.

While a change in combustion chamber design can have an effect on igntion curve attributes, changes to the camshaft, intake manifold, carburetor, and/or static and dynamic compression ratios are also valid considerations and will typically prove to be more significant.  Spark plug placement is the biggest player in combustion chamber design as far as necessitating changes in total timing or the curve itself.  Because of the myriad of combinations in regard to combustion chamber, camshaft, intake manifold, carburetion, etc., it would be difficult at best to nail down any specifics in regards to an optimum curve if simply bolting on the new heads.  A range of ignition curves is something that can be considered after the heads are tested on a variety of combinations but this kind of testing is expensive unless being sponsored so there’s a good chance it will not happen in the near future.  And even with the main stream engines, you don’t see this kind of testing with the published results.  Short term, the heads will be simply tested on what will be considered a normally hopped up Y engine (aftermarket camshaft and intake) and not a variety of combinations.

Optimum total timing for the combination that is tested will be a given though and if significantly different than with using the oem cast iron heads, then that information can be provided with the cylinder heads so the end user can make the appropriate judgement call on whether their own combination warrants a similar adjustment.

A chart for head milling or recommended cut for a 1cc reduction is doable though.

I do know that the set of AFR heads I bought for my 393 windsor had general recomendations.

Just speaking a bit from experience, my cousin developed and had cast a cylinder head for tractor pulling. It developed a bunch more power than previously atainable, but you know the racers ( at 25k+ a pop) knew more than the guy that designed it. After changing valve sizes etc etc throughly ruined the set up and then it was the  the vendors fault.

I can and will run my combination through my Engine Analyser Pro software to get some starting points.

I am working with some of the newer heads that like a total timing of 26° which is by lieu of the spark plug placement so I’m not clueless in this regard.  The testing for the new heads will quantify if current ignition curves are adequate or if a warning statement must be included where ignition timing attributes must be addressed.