The writing on the block….

[Sport/Truck]

After cleaning off the engine, I found some writing on the block
I found this painted on both sides of the block. What is this? Is this the equivalent to the writing in the firewall bay of Chevy’s? BTY do GMC’s have the writing on them?
I have the block numbers and I’m trying to figure out if it’s the original engine or not. 65-72 chevytoys gave me a link to help me with matching the numbers.
Thanks,
s/t

[jsbgump]

Maybe a wreckin yard engine or a rebuilder put those markins there

[Sport/Truck]

So how does one tell if it’s been rebuilt? I would have thought that the small clips on the oil pan (for the plug wires) would have been MIA. And most likely the heat shield would have been scraped. It was such a PITA to get it off I would wonder why anyone would try to put it on.
s/t

[dave2953]

The original 307 that came in my truck had .030" scribed into the top of the pistons. Not sure if this is commonplace, but it might be worth checking.

[rage'nrat638]

o yea i have seen that before..

stands for TOTALY BADA$$ CHEVY J/K dean. it sounds good tho

[PrinsGMC]

If the pistons have 30 stamped in them they are 0.030" over piston so its is rebuilt, look on all the flat surfaces on the block for letters stamped. I know when we rebuild an engine we mark AP(action parts) and then the date of compleation. I think we put it where the oil pan bolts on

[PrinsGMC]

if you look close you can see "30" near the centre of the piston

[Sport/Truck]

Here’s something interesting the TBC is also on the block here.

[Sport/Truck]

Originally Posted by PrinsGMC

If the pistons have 30 stamped in them they are 0.030" over piston so its is rebuilt, look on all the flat surfaces on the block for letters stamped. I know when we rebuild an engine we mark AP(action parts) and then the date of compleation. I think we put it where the oil pan bolts on

I was hoping to try and determine this without pulling it apart.
What about the stock timing chain? Can someone post a picture or describe what it looks like? could this be a clue?
s/t

[PrinsGMC]

If it has a double timing chain it is not stock

[PrinsGMC]

Im fairly sure on that, I havent seen it anyways and your looks like it does on the second picture

[arkracing]

Originally Posted by Sport/Truck

I was hoping to try and determine this without pulling it apart.
What about the stock timing chain? Can someone post a picture or describe what it looks like? could this be a clue?
s/t

should be a single chain.

Pull a main cap and check the back side of the bearing. if it says "GM 400" or something with "GM" on it - it's probably stock. If it says .001, .002, .010, .020, .030 - then the crank has been cut and messed with.

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

[Sport/Truck]

Originally Posted by PrinsGMC

Im fairly sure on that, I havent seen it anyways and your looks like it does on the second picture

I just replaced it. but the old one was weird looking.

[larry may]

That looks like a suffix to me.vi203tbc. There is a way to check suffix at nasty z-28.com

[arkracing]

Originally Posted by larry may

That looks like a suffix to me.vi203tbc. There is a way to check suffix at nasty z-28.com

See above post - I copied the info from NastyZ with the 3 possibilities.

[larry may]

http://www.nastyz28.com/gm-chevy-cod...s-suffix-6.php

Click on this link scroll down till you see TCB. Good Luck

[Sport/Truck]

Originally Posted by arkracing

should be a single chain.

Pull a main cap and check the back side of the bearing. if it says "GM 400" or something with "GM" on it - it's probably stock. If it says .001, .002, .010, .020, .030 - then the crank has been cut and messed with.

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

I’m having a hard time with the date code. Not sure how to read it. It’s on the back near the p-side, right? I’ll go take a picture of it

[Sport/Truck]

Thanks to everyone for the help with this. I took a few pictures of maybe the date code?
And a not so good picture of the main cap, if this could tell us anything I’ll go clean it off and take another one.
I’ll be doing the rear main seal so I’ll be able to check for the info for over size on the cap.
s/t

[larry may]

The block appears to have been produced on the 12 th day of March in the 7th hour of that shift of work .According to the time clock and the suffix. Not sure of the year. Could have been 1969 .Hope this helps..

[brak]

If you go to Ellendale North Dakota you will find TBC (Trinity Bible College)

But i don't think they produce engines or have a signature model

[arkracing]

Originally Posted by larry may

The block appears to have been produced on the 12 th day of March in the 7th hour of that shift of work .According to the time clock and the suffix. Not sure of the year. Could have been 1969 .Hope this helps..

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

anyway in your first picture - where it "looks" like there are tags riveted or screwed to the block - the second one says "L 2 ?" I can't make out the last number - "9" or "0" or "?"

L = December
2 = December 2cd
? = Year - if it is a "0" then it would be a late '70 block and correct for your '71 - but it doesn't appear to be a "0" - but I could be wrogn sometimes casting numbers are hard to make out.

9 would be '69 or '79, 0 would be '70 - which would make since according to the TBC

[larry may]

[QUOTE=arkracing;2009150]???? 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 .

[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?

[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.

[WorkinLonghorn]

I had the original 350 go in my '69 recently and the timing chain was aluminum with nylon,and it had fallen apart and slipped a lot on the cam sprocket.( Why can't they make things that last?) I believe that the O.E. chains were all like this.If you have a regular steel or double chain,it is a re-build afaik.