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Camaro Research Group Discussion => General Discussion => Topic started by: ericisback on July 29, 2020, 11:19:26 AM

Title: "T" or "P" by engine block casting number?
Post by: ericisback on July 29, 2020, 11:19:26 AM
What does the "T" or "P" by the engine block casting number signify?:


(https://i.ibb.co/sKzwH7S/CCF80442-0-BFD-4002-96-E0-200-B83743152.jpg) (https://ibb.co/jysMRtK)


Thanks for any help!
Title: Re: "T" or "P" by engine block casting number?
Post by: bcmiller on July 29, 2020, 03:26:24 PM
Tonawanda.
Title: Re: "T" or "P" by engine block casting number?
Post by: ericisback on July 29, 2020, 07:24:59 PM
Tonawanda.

Well, I think the 427 came from Tonawanda too, but they have a "P" cast next to the casting number:

(https://i.imgur.com/pWp59Yy.jpg)


If what you say is correct, why wouldn't they have a "T" Stamp as well?!?
Title: Re: "T" or "P" by engine block casting number?
Post by: KurtS on July 29, 2020, 09:32:05 PM
Bergy might know for sure, but I think it's the mold ID.
Title: Re: "T" or "P" by engine block casting number?
Post by: ZLP955 on July 29, 2020, 11:59:49 PM
Were there any block casting differences between Truck and Passenger vehicle engine applications?
Title: Re: "T" or "P" by engine block casting number?
Post by: 69Z28-RS on July 30, 2020, 12:04:15 AM
There was a special designation for 'Performance' big blocks...  HP or P?? or PERF?
Title: Re: "T" or "P" by engine block casting number?
Post by: bcmiller on July 30, 2020, 12:21:41 AM
See attached. From Alan's CBTNs book.

I also learned that as a teenager from the older race crowd guys I was around a lot. And about the CFD used on some of the W motor parts we were always looking for.
Title: Re: "T" or "P" by engine block casting number?
Post by: bcmiller on July 30, 2020, 12:37:28 AM
One thought is that maybe Corvette blocks had something different in the machining process compared to regular passenger blocks? I really do not know. Would be interesting to know if there was a trend. I am 90% sure that blocks for full size are exactly the same as Camaro and Chevelle.

 Personally I have only seen the P on 1968 and earlier blocks. But I have no idea what exact years the P was used, when or if it ended.
Title: Re: "T" or "P" by engine block casting number?
Post by: ericisback on July 30, 2020, 10:26:16 AM
Thanks for this great info.
Title: Re: "T" or "P" by engine block casting number?
Post by: 69Z28-RS on July 30, 2020, 11:32:13 AM
There was a special designation for 'Performance' big blocks...  HP or P?? or PERF?  Or maybe it was Hi PERF and only for certain Corvette big blocks?
Title: Re: "T" or "P" by engine block casting number?
Post by: crossboss on July 30, 2020, 01:40:05 PM
Boys,
Isn't it alleged the 'performance' blocks had a higher nickel content?
Title: Re: "T" or "P" by engine block casting number?
Post by: bcmiller on July 30, 2020, 03:59:48 PM
Years back it was thought there were high nickel blocks. I believe current thinking is that is a myth. Aftermarket blocks are usually higher nickel content.
Title: Re: "T" or "P" by engine block casting number?
Post by: crossboss on July 30, 2020, 05:09:12 PM
Years back it was thought there were high nickel blocks. I believe current thinking is that is a myth. Aftermarket blocks are usually higher nickel content.




I do know some of the brand X blocks were. So, I assumed Chevy/GM followed the same process. Guess not.
Title: Re: "T" or "P" by engine block casting number?
Post by: ZLP955 on July 30, 2020, 08:22:08 PM
JohnZ has posted on several occasions about the high nickel Chevy block theory being a myth.
Here's a couple of examples:
http://www.camaros.org/forum/index.php?topic=10311.msg78259#msg78259
http://www.camaros.org/forum/index.php?topic=11078.msg86361#msg86361
Title: Re: "T" or "P" by engine block casting number?
Post by: crossboss on July 30, 2020, 09:06:24 PM
JohnZ has posted on several occasions about the high nickel Chevy block theory being a myth.
Here's a couple of examples:
http://www.camaros.org/forum/index.php?topic=10311.msg78259#msg78259
http://www.camaros.org/forum/index.php?topic=11078.msg86361#msg86361


ZLP955,
Thanks for posting the reference links. Hope my next comments do not go too much off topic...
Interesting, that on the first link it mentions magazine 'test cars' were actually 'ringers'. It happened more than you think. When I spoke to the famous Jim Wanger of Pontiac fame, man did he have stories to tell. The most controversial was the GTO VS Ferrari battle. Magazines of the day said 389 cid for the Goat, however in reality it was a blueprinted 421 SD. Another one was the magazine road test 'ringer cars' on Ford's Boss 351 Mustangs.
On the second link, JohnZ mentioned the letters/numbers on the cores from the foundry. This is common on almost all brands to ID what block it references to. That again, is common practice among all brands.
Title: Re: "T" or "P" by engine block casting number?
Post by: maroman on July 30, 2020, 09:13:51 PM
The red SS '67 Camaro that Hot Rod tested for about 6 months was another. Hot Rod admitted at their 75th ann. That the car actually had a built 427 and all the time slips were trimmed.
Title: Re: "T" or "P" by engine block casting number?
Post by: JKZ27 on July 31, 2020, 01:58:45 AM
I know this discussion is about the T and P but may I ask if anyone knows what the M in a square might be? I have a Flint 327 block and this water pump showing the M near the casting number.
Title: Re: "T" or "P" by engine block casting number?
Post by: ZLP955 on July 31, 2020, 04:37:02 AM
May be similar to the M blocks and heads:
http://www.camaros.org/drivetrain.shtml#BlockCast and scroll down to "M"-Coded Blocks header.
Seems those were evaluation castings rather than date codes, with some being released into production. I have a pair of M-codes 186 heads on my 302.