3917291 info/help

[Jeff_84_Z28]

Curious if anyone can tell me what kind of work may have been done on these. Upgraded springs or whatever can be seen? I’ve never had the heads off so I don’t know if they’re the 1.94 or 2.02’s. Was told the engine was like 12 or 13:1 which I don’t think is the case. Lower end looked like stock rods/crank from what a crappy borescope showed. Were threaded studs ever factory? Other than the stock looking rockers and pushrods, anything stand out to somebody who knows what they’re looking at? Im in my mid 40’s so these are a little bit before my time 

I know they’re not the best pictures. I was more concentrated on the casting numbers. March 68 casting

Thanks!
Jeff

[Jeff_84_Z28]

Couple of other pictures back from 2007 when I put the motor in, I haven’t had the intake off since so it’s the only ones I got showing heads. And if anybody can tell me what that engine pad stamping means? I assume whoever rebuilt it stamped their own serial numbers maybe? Picture showing the block casting number was from before I painted the motor

[bcmiller]

Do you have the block casting date?

Your pad stampings don’t mean much to me. Can you carefully clean off all of the paint from the pad? Might have been stamped by the machine shop during rebuild.

Screw in studs were not available originally on any small block heads for 67-69 Camaros. But many were upgraded over the years.

Can’t definitively tell much about any upgrades to the heads from those pics.

You might try a borescope through the spark plug hole to see the valves.

[Jeff_84_Z28]

Pad # is 51893 A 3187 and looks like no factory stamping letters ive ever seen. This motor was purchased with a 32 ford project by my friends father in the early 90’s. It was purchased from the widow of the guy who started the project. Motor was in bag from machine shop (no paperwork or anything) until the 32 was finished around 2005. I purchased it from him with about 1500 miles in 2007 as he went a different direction with his 32 ford.  I’ll work on getting the date code on block. It’s stamped 010 & 020 in bellhousing which from what I’ve found is the higher nickel content block. Also that pad stamp could be that it was rebuilt 5/18/93, or 3/1/87 maybe? although the 93 date I think would be too late. Pics attached are from 2007 so not the best.

Thanks!

[David K]

It’s hard to see if any work has been done on the heads without pictures inside the valve entry area. Some of those push rods have been reinstalled 180 by looking at them. Probably makes no difference….I’ll let the engine pros chime in.

[bcmiller]

The pad stampings are not factory original. I wanted to see a clear picture of the pad with zero paint anywhere on the pad to see if there is any hint of original stampings.

If you can't bore scope the heads, the only way to tell more is to take them off.

[Petes L48]

The "high nickel content" 3970010 block is a myth.  See Reply 13 in this old thread:

http://www.camaros.org/forum/index.php?topic=18663.msg169269#msg169269

[Jeff_84_Z28]

The pad stampings are not factory original. I wanted to see a clear picture of the pad with zero paint anywhere on the pad to see if there is any hint of original stampings.

If you can't bore scope the heads, the only way to tell more is to take them off.

To the naked eye can make out where it was, but nothing is visible to me.

[bcmiller]

Ok the machining marks from when it was decked are clearly visible now. So yes the letters and numbers stamped there were added at some point. Meaning unknown.