WIW? 1971 NOS 340 block

Posted by: 41MoChev

WIW? 1971 NOS 340 block - 11/13/17 08:18 PM

I'm trying to decide whether to keep and build or sell this block. I need to know if it is valuable for restorations. If I sell it I want to get a fair price. Foundry & date stamping: GM 340P 35060091 (Mound Road Detroit plant, March 4 1971, 91st block that day. Block has never been honed, never had a piston in it (bore 4.0325").

Trying to insert photos. Do they show-up?

https://scontent-iad3-1.xx.fbcdn.net/v/t...amp;oe=5A99A9C6

https://scontent-iad3-1.xx.fbcdn.net/v/t...amp;oe=5A9D42C7

https://scontent-iad3-1.xx.fbcdn.net/v/t...amp;oe=5A9C4CF1
Posted by: fastmark

Re: WIW? 1971 NOS 340 block - 11/13/17 09:22 PM

Looks like a good block to me if it’s NOS. I’d say it’s a $1000 block at least.
Posted by: ScottSmith_Harms

Re: WIW? 1971 NOS 340 block - 11/13/17 10:27 PM

I bought 2 this year, both were good deals at $500.00 each, anything between that and $1000.00 seems fair.
Posted by: 41MoChev

Re: WIW? 1971 NOS 340 block - 11/14/17 08:01 AM

$1,000 is kind of a decision point for me. If it is not worth at least $1000 I'll keep and build it and put in my '41 Chevy. Before I sell or build I will get it checked by a machine shop just to make sure there is nothing wrong with it.

https://scontent-iad3-1.xx.fbcdn.net/v/t...amp;oe=5A92286C

https://scontent-iad3-1.xx.fbcdn.net/v/t...amp;oe=5A90F98F

https://scontent-iad3-1.xx.fbcdn.net/v/t...amp;oe=5A683F8F
Posted by: ScottSmith_Harms

Re: WIW? 1971 NOS 340 block - 11/14/17 08:34 AM

It has a VIN# stamped into it so it's used, not NOS
Posted by: fastmark

Re: WIW? 1971 NOS 340 block - 11/14/17 10:00 AM

That is a new deal now. It a used block. Now we have to know the exact condition of the block to determine the price. The main thing being the ACTUAL bore size, done with a mic at the largest point on the cly wall. Check at the top of the bore with an ID mic right where the ring travel stops. That will tell you what size it is and how far it needs to be bored over.
Posted by: fk5hemi

Re: WIW? 1971 NOS 340 block - 11/14/17 10:40 AM

Hell, if you could get $400 for that block, it would go a long way into rebuilding a 350.
Posted by: minivan

Re: WIW? 1971 NOS 340 block - 11/14/17 04:06 PM

Originally Posted By ScottSmith_Harms
It has a VIN# stamped into it so it's used, not NOS


Oh Scott, you just ruined this guys visions of "Mecum" millions.... LOL
Posted by: 41MoChev

Re: WIW? 1971 NOS 340 block - 11/14/17 06:04 PM

I took it to a machine shop this morning for a complete evaluation. If it turns out to be a run of the mill used block, only worth $400 - $500, I'll be happy to bore it, stroke it, and put in my '41 Chevy; no regrets or second thoughts.
Posted by: 41MoChev

Re: WIW? 1971 NOS 340 block - 11/14/17 06:13 PM

Originally Posted By fk5hemi
Hell, if you could get $400 for that block, it would go a long way into rebuilding a 350.


oh the sacrilege! eek One way or another the old Chevy is getting Mopar motivation. Gotta' turn the tables on the Chevy guys. grin
Posted by: 41MoChev

Re: WIW? 1971 NOS 340 block - 11/14/17 06:21 PM

Originally Posted By minivan
Originally Posted By ScottSmith_Harms
It has a VIN# stamped into it so it's used, not NOS


Oh Scott, you just ruined this guys visions of "Mecum" millions.... LOL

cry cry And I thought I had hit the jackpot! drinking
whistling
Posted by: minivan

Re: WIW? 1971 NOS 340 block - 11/14/17 06:46 PM

Originally Posted By 41MoChev
Originally Posted By minivan
Originally Posted By ScottSmith_Harms
It has a VIN# stamped into it so it's used, not NOS


Oh Scott, you just ruined this guys visions of "Mecum" millions.... LOL

cry cry And I thought I had hit the jackpot! drinking
whistling


Your a good sport..... bow
Posted by: 68427vette

Re: WIW? 1971 NOS 340 block - 11/15/17 08:33 AM

scott, what does this block go into,, im looking for a 71 340/block, for a 71 challenger,
Posted by: ScottSmith_Harms

Re: WIW? 1971 NOS 340 block - 11/15/17 09:29 AM

What is the SPD of your 71 68427vette?
Posted by: 71GTX471

Re: WIW? 1971 NOS 340 block - 11/15/17 06:38 PM

Id trade you a 76 4 bolt main 350 block for it.
Posted by: 41MoChev

Re: WIW? 1971 NOS 340 block - 11/15/17 09:06 PM

Originally Posted By 71GTX471
Id trade you a 76 4 bolt main 350 block for it.


Thanks, but I'm not interested in any SBC. It's gotta' be Mopar power.
Posted by: 41MoChev

Re: WIW? 1971 NOS 340 block - 11/16/17 02:02 PM

Originally Posted By ScottSmith_Harms
It has a VIN# stamped into it so it's used, not NOS


After some research I found that the stamping is the last eight digits of the VIN and mean: 1971, Dodge Main Hamtramck, then sequence built. But you probably already knew that.

https://moparcarparts.com/ENGINEiDENT

I will post the results of the machine shop findings when I get them.
Posted by: 41MoChev

Re: WIW? 1971 NOS 340 block - 12/06/17 12:33 PM

Originally Posted By 41MoChev
Originally Posted By ScottSmith_Harms
It has a VIN# stamped into it so it's used, not NOS


After some research I found that the stamping is the last eight digits of the VIN and mean: 1971, Dodge Main Hamtramck, then sequence built. But you probably already knew that.

https://moparcarparts.com/ENGINEiDENT

I will post the results of the machine shop findings when I get them.


UPDATE: Machine shop just finished checking the block. Good news is that they verified it is standard bore (4.04), good pressure check, crank journal alignment good, and block surfaces are good. As I stated originally, this block has no wear and has never been honed. Why it was serialized and never built and installed is still a mystery. Now the bad news. There is some pitting in the cylinder walls due to storage and moisture. Machine shop estimates it will take 0.030-over to clean it up.
Jim
Posted by: ScottSmith_Harms

Re: WIW? 1971 NOS 340 block - 12/06/17 03:43 PM

Quote:
. Why it was serialized and never built and installed is still a mystery.


Its not a mystery, showing wear (or not) the assembly date verifies that it was once assembled, and if it has a VIN# stamping it was installed into a car as well.
Posted by: Alaskan_TA

Re: WIW? 1971 NOS 340 block - 12/06/17 04:16 PM

It is from a 1971 Cuda.
Posted by: EV2Bird

Re: WIW? 1971 NOS 340 block - 12/06/17 05:08 PM

Why it was serialized and never built and installed is still a mystery.

If-s, maybes, should of-s, this is odd, although ive never had a mystery come into play, but all the others have in the end simply cost me extra money or more then not wasted money.

If it were mine id toss it on CL at the going rate of a used block, suggest the buyer bring any tool he needed to measure and make a decision and sell it as is, where is.
Posted by: 41MoChev

Re: WIW? 1971 NOS 340 block - 12/06/17 07:23 PM

Originally Posted By ScottSmith_Harms
Quote:
. Why it was serialized and never built and installed is still a mystery.


Its not a mystery, showing wear (or not) the assembly date verifies that it was once assembled, and if it has a VIN# stamping it was installed into a car as well.


Well then... if so, the mystery is; why did they build the engine without honing the cylinders? Maybe that is why they took it out before there was any wear. It would have smoked and used a bit of oil... Maybe there is another explanation. Were there no anomalies at the Chrysler plants back in the day? Could it have been a replacement block, sent to a dealer and never assembled for some reason? One thing I have learned in my profession (QA) is that just because there is a process, doesn't mean that it is always followed with no exceptions.
Posted by: Alaskan_TA

Re: WIW? 1971 NOS 340 block - 12/06/17 07:27 PM

Honing marks disappear with wear.

Check my previous post too if you missed it? ;-)
Posted by: 76orangewagon

Re: WIW? 1971 NOS 340 block - 12/06/17 08:28 PM

P.M sent...
Posted by: EV2Bird

Re: WIW? 1971 NOS 340 block - 12/06/17 09:07 PM

Why did they build the engine without honing the cylinders?

Dude they didnt, get a grip.

Really with the revelation of its deep pitting id say if anything they did the old chevy guy trick, use an old boring bar to cut a couple thousands of ugly out of it to make it look fresh.

Do you even know what a real NOS 340 block bore measures out to before honing? Clearly not.

With it being stamped and needing cut .030 just use it and be happy, no lotto ticket to cash in on here.
Posted by: an8sec70cuda

Re: WIW? 1971 NOS 340 block - 12/07/17 08:22 AM

Originally Posted By EV2Bird


Do you even know what a real NOS 340 block bore measures out to before honing? Clearly not.

With it being stamped and needing cut .030 just use it and be happy, no lotto ticket to cash in on here.

iagree If it had never been honed, it would not be at standard bore.
Posted by: 41MoChev

Re: WIW? 1971 NOS 340 block - 12/07/17 09:48 AM

Originally Posted By EV2Bird
Why did they build the engine without honing the cylinders?

Dude they didnt, get a grip.

Really with the revelation of its deep pitting id say if anything they did the old chevy guy trick, use an old boring bar to cut a couple thousands of ugly out of it to make it look fresh.

Do you even know what a real NOS 340 block bore measures out to before honing? Clearly not.

With it being stamped and needing cut .030 just use it and be happy, no lotto ticket to cash in on here.


Well, you guys are awesome and clearly knowledgeable and correct. Not looking for a "lotto" ticket; just wanting to know what I have before I waste it by putting it in a Chevy.
Posted by: 41MoChev

Re: WIW? 1971 NOS 340 block - 12/07/17 10:01 AM

"
Do you even know what a real NOS 340 block bore measures out to before honing? Clearly not."

I do not; so please educate me. What does a real NOS 340 block measure out to before honing? I am just curious.... Thanks again for sharing your knowledge.
Posted by: EV2Bird

Re: WIW? 1971 NOS 340 block - 12/07/17 10:19 AM

Rough from the foundry, if you could find one, can be a small as 4.00, machine shop rough could be in the low 4.03-s.

Modern shops leave .003-.005 to hone.

If it were an over the counter ready to build block it would already be honed.

One of my nos 318 based race blocks should be 3.91 and its rough at 3.87.

You and the machine shop would spot factory unfinished a mile away, small bore and very very rough machine work, you would see and fell the ridges along the whole bore.

And these blocks in rough shape would have no vin on the pad.

If its not too hard to get to I will post pics later today.
Posted by: 41MoChev

Re: WIW? 1971 NOS 340 block - 12/07/17 03:04 PM

UPDATE: I just picked the block up from the machine shop. The machine shop owner (30 years experience in automotive machining) stated that it appeared to never have been built. Bores are exactly 4.04. There are no hatch marks, no visible or measurable wear. He agreed that due to the serialization it probably had been built and installed in a new car. His guess is that the car was totaled with less than 2,000 miles on it and parted out. Engine must have been disassembled, parted, and the block cleaned removing all traces of paint.
Now that is the most plausible explanation so far...

Unfortunately; the block sat somewhere for years without proper protection and developed the pitting in the cylinder walls. No big deal; I will just build it .30 over and be happy with it in my Chevy.
Posted by: Alaskan_TA

Re: WIW? 1971 NOS 340 block - 12/07/17 03:34 PM

Look on the front of the block below the driver side head surface & there will be another series of numbers that was stamped after the engines final assembly, including the date it was done.

It likely starts GM 340 P & then two sets of 4 numbers each.
Posted by: hemicar1971

Re: WIW? 1971 NOS 340 block - 12/07/17 04:10 PM

Sell the 1971 340 block to someone that needs it or thinks they need a 1971 340 Block if you are building a big cube small block. Start with a 360 block that costs a lot less than a so called date coded 1971 340 block. Buy a stroker kit and make 400 plus cubes and buy a nice set of heads with some work. The 1971 Block means nothing to you but a price tag so sell it and get some money to build the motor you want. If you advertise the serial number on the pan rail maybe the original body can be found to the motor and the owner might pay you a little more money.
Posted by: 41MoChev

Re: WIW? 1971 NOS 340 block - 12/07/17 04:16 PM

Originally Posted By Alaskan_TA
Look on the front of the block below the driver side head surface & there will be another series of numbers that was stamped after the engines final assembly, including the date it was done.

It likely starts GM 340 P & then two sets of 4 numbers each.


See page 1, original post and photos: "Foundry & date stamping: GM 340P 35060091 (Mound Road Detroit plant, March 4 1971, 91st block that day."

Yes, this must prove it was assembled. I'm going with the theory that the car was wrecked right after it drove off the lot. Not too unlikely. Maybe daddy bought it for his 16 year old who punched it and did a 360 totaling the car. Wouldn't be the first time for that scenario. drive
Posted by: Alaskan_TA

Re: WIW? 1971 NOS 340 block - 12/07/17 04:20 PM

Aha.

I missed that, sorry.
Posted by: EV2Bird

Re: WIW? 1971 NOS 340 block - 12/07/17 06:52 PM

Also, although late now if it had been a nos block it would of had factory freeze plugs in it, a little diamond I think with a p in the middle and always when in doubt, look at inside at the water jackets (cylinders) as even if antifreeze was used they still stain.

A block is only "new" one time and its pretty easy to spot the smaller details.
Posted by: hemicar1971

Re: WIW? 1971 NOS 340 block - 12/07/17 07:04 PM

The Vehicle could of been in an accident and the drive train pulled and the body sent to the wreckers. It could of sat in the wreckers for years and years and bought later in life and is now back on the road. Just read about the A12 1969 Super Bee Mod Top that was dragged out of the southern USA Auto Wreckers and up to Canada and then sold back into the USA. I sold an A12 Road Runner to a friend 30 years ago body only and he was contacted last year by a person that had the original motor to the A12. Things happen for the good sometimes with information on the internet.

BS23H1B345752 could be the vehicle the motor was from.
Posted by: 41MoChev

Re: WIW? 1971 NOS 340 block - 12/08/17 07:30 AM

Originally Posted By EV2Bird

With it being stamped and needing cut .030 just use it and be happy, no lotto ticket to cash in on here.


This is the advice I'm going with. You guys have convinced me that the block is no big deal. I didn't buy it to sell it, I bought it to build it. I have always been partial to Mopars; especially the 340 which I have never been fortunate enough to own. Turning the tables on the Chevy guys with a Mopar 340 is just icing on the cake.
Jim
Posted by: plumcrazycuda

Re: WIW? 1971 NOS 340 block - 12/08/17 09:19 AM

I have a block can you tell me what original car was by the vin stamp? The casting date is 5 of 70. And if car is out there by chance! If it is I would sell it for what I have into it. Stamping is 1B157379.
Posted by: 6bblgt

Re: WIW? 1971 NOS 340 block - 12/08/17 12:36 PM

LM29H1B157379 - Dodge Demon 340 drive new to me, I have no info on the car
Posted by: 41MoChev

Re: WIW? 1971 NOS 340 block - 12/10/17 10:25 AM

If you want to trade your block then put it in the proper forum. Not here.
Posted by: WO23Coronet

Re: WIW? 1971 NOS 340 block - 12/10/17 12:40 PM

If you’re set on a 340 then keep the one you have. It makes no sense to sell the one you have just to buy another, unless someone needs the casting date/year and you really want to help them out but it’s just hassle for you. Trading for another block would make more sense than selling for your purposes
Posted by: 41MoChev

Re: WIW? 1971 NOS 340 block - 12/10/17 09:40 PM

Originally Posted By 41MoChev
If you want to trade your block then put it in the proper forum. Not here.


Sorry, I didn't understand that WIW is just for money value. I did not say I wanted to trade the block. I still want to keep it, but I am willing to consider a trade to help someone who might need the block for a restoration. WIW in trade seemed appropriate. I'm not wasting my time posting it for sale or trade when that is not really what I am looking for.
Posted by: EV2Bird

Re: WIW? 1971 NOS 340 block - 12/10/17 10:26 PM

A machined ready to build 360 block (possibly just bored, letting your shop hone it for your piston/ring selection) and they would have to bring it or pay the freight for both imo.

That would be about it for me, but honestly in a case like this id save the possible bs and headache and just move on to build the 340.