Author Topic: "T" or "P" by engine block casting number?  (Read 5243 times)

ericisback

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





Thanks for any help!
67 Corvette 427 conv. -  https://bit.ly/2yykRW7
67 GTO 400 conv. - 68 Camaro 396 conv.
69 R-Code Mach 1 - 78 VW Beetle conv.

bcmiller

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Re: "T" or "P" by engine block casting number?
« Reply #1 on: July 29, 2020, 03:26:24 PM »
Tonawanda.
Bryon / 1968 Camaro SS 396 coupe - now old school 468 big block
1967 Camaro RS/SS 396 coupe L35/M40 - 4 generation family project
Looking for 68 Camaro with body # NOR 181016

ericisback

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Re: "T" or "P" by engine block casting number?
« Reply #2 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:




If what you say is correct, why wouldn't they have a "T" Stamp as well?!?
67 Corvette 427 conv. -  https://bit.ly/2yykRW7
67 GTO 400 conv. - 68 Camaro 396 conv.
69 R-Code Mach 1 - 78 VW Beetle conv.

KurtS

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Re: "T" or "P" by engine block casting number?
« Reply #3 on: July 29, 2020, 09:32:05 PM »
Bergy might know for sure, but I think it's the mold ID.
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ZLP955

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Re: "T" or "P" by engine block casting number?
« Reply #4 on: July 29, 2020, 11:59:49 PM »
Were there any block casting differences between Truck and Passenger vehicle engine applications?
Tim in Australia.
1969 04A Van Nuys Z/28. Cortez Silver, Dark Blue interior, VE3, Z21, Z23, D55/U17, D80, flat hood.
Sold at Clippinger Chevrolet in Covina, CA.
AHRA Formula Stock at Lions Dragstrip, NHRA E/MP at Pomona Raceway

69Z28-RS

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Re: "T" or "P" by engine block casting number?
« Reply #5 on: July 30, 2020, 12:04:15 AM »
There was a special designation for 'Performance' big blocks...  HP or P?? or PERF?
09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette, '60 Corvette, '72 Corvette
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan

bcmiller

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Re: "T" or "P" by engine block casting number?
« Reply #6 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.
Bryon / 1968 Camaro SS 396 coupe - now old school 468 big block
1967 Camaro RS/SS 396 coupe L35/M40 - 4 generation family project
Looking for 68 Camaro with body # NOR 181016

bcmiller

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Re: "T" or "P" by engine block casting number?
« Reply #7 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.
« Last Edit: July 30, 2020, 04:02:08 AM by bcmiller »
Bryon / 1968 Camaro SS 396 coupe - now old school 468 big block
1967 Camaro RS/SS 396 coupe L35/M40 - 4 generation family project
Looking for 68 Camaro with body # NOR 181016

ericisback

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Re: "T" or "P" by engine block casting number?
« Reply #8 on: July 30, 2020, 10:26:16 AM »
Thanks for this great info.
67 Corvette 427 conv. -  https://bit.ly/2yykRW7
67 GTO 400 conv. - 68 Camaro 396 conv.
69 R-Code Mach 1 - 78 VW Beetle conv.

69Z28-RS

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Re: "T" or "P" by engine block casting number?
« Reply #9 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?
09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette, '60 Corvette, '72 Corvette
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan

crossboss

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Re: "T" or "P" by engine block casting number?
« Reply #10 on: July 30, 2020, 01:40:05 PM »
Boys,
Isn't it alleged the 'performance' blocks had a higher nickel content?
Just another T/A fanatic. Current lifelong projects:
1968 Olds 442 W-30
1969 Mustang Fastback w a Can-Am 494 (Boss 429)

bcmiller

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Re: "T" or "P" by engine block casting number?
« Reply #11 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.
Bryon / 1968 Camaro SS 396 coupe - now old school 468 big block
1967 Camaro RS/SS 396 coupe L35/M40 - 4 generation family project
Looking for 68 Camaro with body # NOR 181016

crossboss

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Re: "T" or "P" by engine block casting number?
« Reply #12 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.
Just another T/A fanatic. Current lifelong projects:
1968 Olds 442 W-30
1969 Mustang Fastback w a Can-Am 494 (Boss 429)

ZLP955

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Re: "T" or "P" by engine block casting number?
« Reply #13 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
Tim in Australia.
1969 04A Van Nuys Z/28. Cortez Silver, Dark Blue interior, VE3, Z21, Z23, D55/U17, D80, flat hood.
Sold at Clippinger Chevrolet in Covina, CA.
AHRA Formula Stock at Lions Dragstrip, NHRA E/MP at Pomona Raceway

crossboss

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Re: "T" or "P" by engine block casting number?
« Reply #14 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.
Just another T/A fanatic. Current lifelong projects:
1968 Olds 442 W-30
1969 Mustang Fastback w a Can-Am 494 (Boss 429)