Block numbers--help me decode possibilities?

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Dec 5, 2013 | 06:17 PM

#21

63mako

Race Director

Joined: May 2005

Posts: 10,674

Likes: 122

From: Millington Illinois

St. Jude Donor '08-'09

Quote:

Originally Posted by 63mako

Drivers side rear near the casting number. Example: C270 is a March 27 1970 casting. 3970010 was used 1968 327 and 1969-1979 350 only.
http://www.nastyz28.com/sbchevy/sblo...a_close_button
3970010 (1969-1979 350) combined with CTB can only be a 1970 High performance 350 LT1 W/4speed. NICE!!!
http://www.nastyz28.com/gm-chevy-cod...s-suffix-3.php

After some additional research this is definitely a 1970 LT1 out of a Camaro, Chevelle or Nova with a 4 speed transmission (extremely rare). I thought the LT1 was Corvette, Camaro only but according to the above links the 3970010 was 350 ONLY after the 3 digit stamp code was instituted and the ONLY 3 digit stamp code CTB in ANY 350 was as I list above. Can't find the CTB code or a LT1 listed for any 1970 Chevelle, Nova, Camaro in my 1968-1975 Chilton though , just on the NastyZ28 site above.

EDIT: Here is the CTB listed as the 1970 Z28 360 HP 350 manual trans. Only made 8733 of them.
http://www.nastyz28.com/camaro/camar...a_close_button

EDIT. Here it is listed as optional in 1970 Nova but COPO only (NOT ON OPTION SHEET). Only 177 COPO of which I bet most or all were Big Blocks. No evidence of this engine ever installed in a Nova. If you got one keep it.
http://www.oldride.com/library/1970_chevrolet_nova.html

EDIT: Never used in Chevelle. (NOT ON OPTION SHEET). Not listed as optional or COPO. No evidence of this engine ever installed in a Chevelle. If you got one keep it.
http://www.chevelles.com/shop/options.html

This is one of 8733 LT1's originally installed in a 1970 Camaro Z28 with manual trans.

Last edited by 63mako; Dec 6, 2013 at 09:44 AM.

Dec 5, 2013 | 08:37 PM

#22

BKarol

Melting Slicks

Joined: Sep 2004

Posts: 3,223

Likes: 666

From: Northeast

Quote:

Originally Posted by Mike7143

Or if this is the case, and it's not the conveyor number, then it'd be pattern serial number 32 from mold/series 3?

Can only tell you what was written in the NCRS Corvette Restorer magazine article about the conveyor # and notes written on pictures by Roger Wilson, Gen. Supv. Pattern Shop, Saginaw Metal Castings OP.

My friend actually visited the plant and made contact with a few people afterward before writing an article @2001. He got this information while researching another subject.

Good luck to the OP and the thread at least will give you some insight into what some numbers mean.

Dec 5, 2013 | 10:38 PM

#23

Mike7143

Instructor

Joined: Jan 2013

Posts: 237

Likes: 0

From: Indianapolis Indiana

Thanks for your info source karol! Both seem equally true, let's wait for Easy Mike's source!

But like karol said, hopefully the OP can source the original home of his block as well as learn a good deal about block casting codes and symbols! I know I sure have!