The writing on the block….

[72dually]

I have the same block 2 days later than yours although mines a TBB, and its an early 1970

Either you have a 1970, or I actually have a 1971

Im going by what my build sheet date says, unless Im reading it wrong.

[72dually]

Block, and build sheet

[Sport/Truck]

Originally Posted by ghackett1

I'm pretty sure the letters on your block are the engine suffix code which denotes what it is and what it is for. The set of numbers I don't know. It is part of you vin sequence number maybe?

I'll check that & let you know.
s/t

[72dually]

Thats a december 69 350.........so an early 1970 motor
I didn't see the cylinder head dates

In my case, I have a November 69 casted block K18, with December L 3 69 heads.

The actually engine pad stampings were done last on the assembly line

Block
heads
accessories

Normally the dates between the heads, intake, carb, etc., are within a week of each other

[Sport/Truck]

What documentation can be used to identify original equipment? Protect o plate? Build sheet?(I haven’t looked for that yet).

[Sport/Truck]

Originally Posted by arkracing

should be a single chain.

Looks stock to me. Although not common I have seen "paint markings" like that on some Small Blocks. The fact that it matches the Stamping on the Front pad indicates it is probably original.

What is the date code on the block: that will narrow it down
TBC = 1970 350 convfwd cabs, a/t , 255hp, 4bbl, C-10 to 3500
TBC = 1970 350 m/t, 3 spd, 255hp, 4bbl, K-10 & 20
TBC = 1979 350 conv. cab, m/t,fed L LS9 165hp, 4bbl, C-10 to 2500

Originally Posted by 65-72 chevytoys

Unfortunatly you do not have a numbers matching truck. Ususually the yellow marks are from the grease pens that junkyards use to mark their inventory. The TBC came out of a 1970 truck and the number for the heads you gave me were for 1971 and 1972 only.

Not sure what to think of this?

[Sport/Truck]

In my original PM I sent, I listed a wrong number.
so I rechecked the heads number, I had originally called a 3 an 8. The number is 3973487. Are these heads matching now? Are they any good?

Since the block was assembled in December, 1970 the the truck was sold off the lot in Feb, 2nd 1971. You think the block casting would still be 1971? I don’t know.
s/t

[arkracing]

[QUOTE=larry may;2009162]

Originally Posted by arkracing

???? 7th hour of that shift??? where are you getting that? the clock thing only has 10 markings?

Exactly. The pointer starts the shift inside the rivets the rivet outside the circle says what hour of the shift the block was cast. Count clockwise. Do not bother trying to get a pi$$ing contest going . Read the publications .

Wasn't trying to get a pi$$ing contest going - I honestly didn't know that's how you read that. I always use the actual casting date. I never even knew how to decode that thing. Can you link someplace where it explains how to decode that thing?

[arkracing]

Sport/Truck -

I'll get a picture for you this weekend of a '79 350 that has Yellow makings on it from the Factory - they are much nicer appearing than the ones on your motor (they look like they were stencils)

If the motor was cast in december of '70 and the truck was sold in Feb of '71 would make sense

it's like buying a '07 car in July/August of '06

I had a 396 Block where the Front Pad code indicated '68 Chevelle - the Casting Date was December of '67 so the block was made in '67 but put into a '68 car

Here is the the decoded head information:
3973487....71-72...350..........used on 71-72 350 LT1, 75cc chamber
3973487X...71-72...350..........75cc chamber

I still think it is the original motor - but what the heck do I know. what's the actual casting number on the block? - driver's side rear? and what is the casting date "L 2 ????" I couldn't make out the last number.

[Sport/Truck]

The casting # wasn’t in the picture? That is L 2 from what I can tell. What does this mean?
s/t

Oh, I got’ya the last number looks like a 0? I’ll look again when I get home.

[CrashEd]

Heres a place to desiffer suffix code V1203TBC

And here you can find the year by the TBC

And on the writing on the block i have 400 small block that has the same thing . It has the suffix code in that same color grease marker and its not from a junk yard. It would be nice to know all the crazy things chevy did in there factorys. I know there will be someone tair down a grain bin some day and wander what Ed stands for

Ed

[72dually]

The heads you have match up providing they are L 2 70.

If the casting date of the block actually says 0 then its most likely original to the truck, and would be a late december 70 block which is correct for an early 71 truck


It appeared to be a 9, but its real hard to tell??

[CrashEd]

From what i can find i would say the block was cast the 12 month 03 day of 1970. Then the motor was assembled in 1971 and got heads 3973487 for 71-72 trucks and then it went in a 71 truck.

Is the casting # on the block 3970010 that block was from 69-80

Them 3973487 heads a good there the big chamber 76cc. thats the best of the big chamber heads i think. Probaby 1.94-1.50 valves.

[65-72 chevytoys]

Originally Posted by CrashEd

From what i can find i would say the block was cast the 12 month 03 day of 1970. Then the motor was assembled in 1971 and got heads 3973487 for 71-72 trucks and then it went in a 71 truck.

Is the casting # on the block 3970010 that block was from 69-80

Them 3973487 heads a good there the big chamber 76cc. thats the best of the big chamber heads i think. Probaby 1.94-1.50 valves.

THis is the same as what I said when you PM me. Yours was kind of hard because the TBC was for 1970 model year only with 1971-1972 model year heads. But because of the assmbley date so late in the year 12 03 1970 then the 1971 heads were put on last and placed in a 1971 truck. This would have been a lot easier if all the casting dates were the same. But because they were different you had to follow the assembly timeline. Like I said the decoding of the numbers is the easy part. Matching all the parts from the dates together is sometimes and art.

[larry may]

[QUOTE=arkracing;2009397]

Originally Posted by larry may

Wasn't trying to get a pi$$ing contest going - I honestly didn't know that's how you read that. I always use the actual casting date. I never even knew how to decode that thing. Can you link someplace where it explains how to decode that thing?

http://www.nastyz28.com/sbchevy/sblock.html#cdate See clock information . S/B there when clicking on the link.....The block was cast Nov69
suffix says it was put together nov 3 and probably 1969.

[Sport/Truck]

While getting the block ready for the pan gasket I found these numbers. What do you think they mean? I can’t tell for sure if this motor has been re-done by anything else. I took some pictures of the rods. They have a 0 on them, not sure what that means.
s/t

[Sport/Truck]

Here’s the picture of the rods with the 0 on them (they all have it) and the number on the crank. Is this a forged crank?
s/t

[BowTieMan]

I had the same style yellow writing on the side of my block in my 70. I didn't pay any attention to what it said and just painted over it with chevy orange. But the block was made in 69 and its a 4 bolt main so I am guessing its original to my truck but dont know for sure.

[72dually]

The 442 crank is a cast crank, my 70 gmc motor has the same crank

Steel cranks are easy to identify by the parting line

The common cast iron crankshaft has a narrow parting line seam where the halves of the mold came together as the original casting was made

Forged cranks have a much wider parting lines, and often the appearance that excess metal has been cut or ground away

[72dually]

steel crank parting line

[cooters]

the easiest way to tell if an engine is rebuilt is to check if the connecting rod has the cylinder number stamped in it right next to the cap parting line, gm doesnt stamp them. Also for some reason you will see some motors that were machined wrong and gm put larger pistons in from factory. I ve seen only 1 piston 30 and the rest standard a few times on 68-72 gm

[72dually]

Clean off the top of one of pistons, and see if there any #'s are stamped on them

Here's an example of a +30 over piston

[bigjimzlll]

You have a double roller timing chain on it....so it has atleast had a minor overhaul

[Sport/Truck]

Originally Posted by bigjimzlll

You have a double roller timing chain on it....so it has atleast had a minor overhaul

I just put that on. It was a single.
s/t