Need Help Identifying My Block

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Sep 9, 2009 | 10:35 AM

redman76

Thread Starter

Melting Slicks

Joined: May 2006

Posts: 2,590

Likes: 403

From: Nashville TN

St. Jude Donor '09

Need Help Identifying My Block

My block is not original L48. I pulled some codes from it and here is what I've uncovered so far (L65????). Does anyone have any info to add?

Block - Engine Code t0713ckj CKJ 1973 350 tur hydro trans. L65 - 4 A B F/Bel Air/Kingswd Tonawanda July 13
Block - Partial VIN 13b635904
Block - Casting # 3970010 k 12

I'm in the process of doing a top end rebuild and was measuring the depth of the pistons in the bore at TDC so I can order the correct head gasket. All the feedback that I have gotten suggest the pistons sit too far in the hole. Is this too far down for an L48 or for all SBC? OK, got the block deck cleaned and measured the depth at .040-.050 range on all the cylinders.

Sep 9, 2009 | 11:27 AM

Easy Mike

Team Owner

Joined: Jun 2000

Posts: 38,923

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From: Southbound

Cruise-In II Veteran

Quote:

Originally Posted by redman76

...Engine Code t0713ckj

CKJ indicates a 73-77 350 low horsepower, 4 barrel

Quote:

Block - Partial VIN 13b635904

Plant code of B could be Baltimore.

Quote:

k 12

November 12th, possibly 1973 based on the VIN derivative.

Sep 9, 2009 | 11:28 AM

Mike Ward

Race Director

Joined: Jul 2001

Posts: 15,892

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You might want to reformulate your question and ask again. Your engine was once an L65, no telling what it is now. What exactly are you trying to achieve?

Sep 9, 2009 | 11:54 AM

redman76

Thread Starter

Melting Slicks

Joined: May 2006

Posts: 2,590

Likes: 403

From: Nashville TN

St. Jude Donor '09

I'm really just trying to figure out what I have and how it might impact my top end selection. I'm a little concerned that instead of the expected .025-.032 depth, I have .040-.050 depth. Maybe it's not really that big a deal. Was .040-.050 typical for a L65? Or has this thing really been bastardized. I'll replace the block at some point, so I'm not too worried about it.

Here is a pic of the piston tops if that helps any:

Sep 9, 2009 | 12:54 PM

Solid LT1

Le Mans Master

Joined: Dec 2003

Posts: 5,727

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From: Fremont CA

Motor is a "generic" 4bbl mid 70's 350 Chevy, you would want to use a thin head gasket (steel shim or thin composite under 0.020" thickness) when replacing the cylinder heads. Your best bet would be to check with a local machine shop. You should try to source a set of Vortec, or early small combustion chamber cylinder heads and gain some power for your efforts. You block is a good strting point for a mid 400HP build up, I would use it when you have the $$$ to properly build a motor in the future. Difference between your low compression 190HP 350 and a 1970 300HP 350 is compression, carb and ignition tuning same cam, pistons, rods, ect. If you replace the heds and use common multilayer gaskets you will make your motor into a DOG, use thin head gaskets and it will have the proper quench even with the pistons 0.040" below the deck. You have this motor down this far, may as well change the cam and timing chain if it ran well before you pulled it down.

Sep 9, 2009 | 03:02 PM

redman76

Thread Starter

Melting Slicks

Joined: May 2006

Posts: 2,590

Likes: 403

From: Nashville TN

St. Jude Donor '09

Thanks Solid. My plan is to install 64cc heads with .015 steel shim gasket. Cam/Timing chain is definitely getting replaced too. I have several threads about my top end project if anyone is interested:
Top end rebuild time . . .

Sep 10, 2009 | 01:44 AM

Buddy1980

Racer

Joined: Nov 2008

Posts: 297

Likes: 3

block casting number

My book tells me that 3970010 could be: 69 vette 4-bolt main, or 69 z-28 302 or, 69-79 truck or, 69-79 pass. chevelle, camaro, nova or, 70 vette 300, 350, 370 hp 4 bolt main, or 72 vette 200, 255 hp 4 bolt main. Looks like that number was used on quite a few combinations.