Small Block ID...Help - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**1971Stepside** · 07-15-2002, 08:39 AM

Can someone tell me about this motor based on the numbers? Is it a four bolt and what year? Hopefully these are the correct numbers.....

JimKshortstep4x4 · 07-15-2002, 09:29 AM

Most engine blocks with that code are 4 bolt main engines. If that is a 69-72 block than it is a 4 bolt main engine. (I don't know of any exceptions).

JIm

**68 Stepside** · 07-15-2002, 12:25 PM

Those don't help a whole lot. It could be:
Casting#---CI------YR-Mns-Model
3970010....302.....69....4...Z-28 Camaro
3970010....327.....69....2...Trucks and industrial
3970010....350...69-80...2 or 4

You need the suffix code the front of the block, on the pad in front of the passenger side head, otherwise, it's pretty hard to say what it is.

TJ

bigjimzlll · 07-15-2002, 12:59 PM

I have had 3 of those blocks in the last year...all of them were 2 bolt mains...they usally do have a higher nickle content though..all in all one of the better blocks

**1971Stepside** · 07-15-2002, 01:36 PM

I know it is a 350. I just don't know what year and I am almost positive that it is a 4 bolt as that is what I remember the guy telling me when I bought it. It is not the motor that came in the truck as that was a 6cyl. I am trying to decide if I should have this motor re-built or just by a crate from GM. I want some HP, so I was looking at the ZZ4 engine.

If this is a 2 bolt I will sell it.

What is a 2 bolt worth vs. a 4 bolt?

Southpa · 07-15-2002, 02:41 PM

That casting number spans a lot of years, got it on my block too.
The value is in the nickel content. I was told that the "10" at the end means 10% nickel.

Look at the front pass. side of the block for a machine pad w/ numbers followed by letters (engine suffix code) stamped in. That will give you more specific info on year(s) and application(s).
You can dig up the info at:

http://www.nastyz28.com/spmenu.html

**COBALT** · 07-15-2002, 03:27 PM

Find the ledge in front of the passenger side head (right on the deck). Sometimes it's hidden behind an accessory. Take some brake cleaner and scrub that area clean. There should be a stamped code. The last two or three letters is the suffix. Look that code up to find out what kind of 350 it is.

07-15-2002, 08:39 AM	#1
1971Stepside Almost Satisfied Join Date: Mar 2002 Location: Springfield, MO Posts: 2,932	Small Block ID...Help Can someone tell me about this motor based on the numbers? Is it a four bolt and what year? Hopefully these are the correct numbers..... Attached Images __________________ 1971 C10 Stepside. LSx 6.0 with BTR Stage IV, Speed Engineering Headers, 4L80e transmission w/3200 Circle-D Stall. 3.73. Posi. Purchased this truck when I was 17. I started the rebuild (or take apart) in 1993. I have drug it around all over the country in pieces. Finally back on the road in 2021. "I can't complain, but sometimes I still do. Life's been good to me so far."

07-15-2002, 12:25 PM	#3
68 Stepside huh? Join Date: May 2000 Location: Washington, Illinois Posts: 5,690	Those don't help a whole lot. It could be: Casting#---CI------YR-Mns-Model 3970010....302.....69....4...Z-28 Camaro 3970010....327.....69....2...Trucks and industrial 3970010....350...69-80...2 or 4 You need the suffix code the front of the block, on the pad in front of the passenger side head, otherwise, it's pretty hard to say what it is. TJ __________________ Someday when I'm lonely, Wishing you weren't so far away, Then I will remember Things we said today. RIP El Jay

07-15-2002, 12:59 PM	#4
bigjimzlll Senior Member Join Date: Dec 2001 Location: Redding,CA...USA Posts: 4,736	I have had 3 of those blocks in the last year...all of them were 2 bolt mains...they usally do have a higher nickle content though..all in all one of the better blocks __________________ It's called "drag racing" if they called it "tic..tic..WHAM!..BANG! F*&K!!!", they'd have to keep the magazines under the counter with the other men's publications click the clicky to join the site.... http://67-72chevytrucks.com/vboard/payments.php 67 lwb..first hotrod in 25 years..540 best ET is 9.45 @ 141.44 Anderson,CA

07-15-2002, 01:36 PM	#5
1971Stepside Almost Satisfied Join Date: Mar 2002 Location: Springfield, MO Posts: 2,932	I know it is a 350. I just don't know what year and I am almost positive that it is a 4 bolt as that is what I remember the guy telling me when I bought it. It is not the motor that came in the truck as that was a 6cyl. I am trying to decide if I should have this motor re-built or just by a crate from GM. I want some HP, so I was looking at the ZZ4 engine. If this is a 2 bolt I will sell it. What is a 2 bolt worth vs. a 4 bolt? __________________ 1971 C10 Stepside. LSx 6.0 with BTR Stage IV, Speed Engineering Headers, 4L80e transmission w/3200 Circle-D Stall. 3.73. Posi. Purchased this truck when I was 17. I started the rebuild (or take apart) in 1993. I have drug it around all over the country in pieces. Finally back on the road in 2021. "I can't complain, but sometimes I still do. Life's been good to me so far."

07-15-2002, 02:41 PM	#6
Southpa Registered User Join Date: May 2000 Location: Victoria, BC, Canada Posts: 2,409	That casting number spans a lot of years, got it on my block too. The value is in the nickel content. I was told that the "10" at the end means 10% nickel. Look at the front pass. side of the block for a machine pad w/ numbers followed by letters (engine suffix code) stamped in. That will give you more specific info on year(s) and application(s). You can dig up the info at: http://www.nastyz28.com/spmenu.html __________________ 1970 GMC 1500 Custom Original 350/TH350 Victoria, BC, Canada You can wish in one hand and crap in the other. See which one gets filled first.

07-15-2002, 09:29 AM	#2
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	Most engine blocks with that code are 4 bolt main engines. If that is a 69-72 block than it is a 4 bolt main engine. (I don't know of any exceptions). JIm

07-15-2002, 03:27 PM	#7
COBALT Senior Member Join Date: Sep 2001 Location: Seattle, WA, USA Posts: 5,817	Find the ledge in front of the passenger side head (right on the deck). Sometimes it's hidden behind an accessory. Take some brake cleaner and scrub that area clean. There should be a stamped code. The last two or three letters is the suffix. Look that code up to find out what kind of 350 it is. __________________ '69 3/4 ton C20 2wd-350ci/TH400 '69 3/4 ton Custom 20 2wd-350ci/4sp Manual '99 2wd 5.7 Chevy Tahoe Seattle, WA.

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