how many 71's were 396/auto? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

CUDA8U · 09-21-2018, 11:49 AM

I found a 71 396 auto,how many were made?

**71CHEVYSHORTBED402** · 09-21-2018, 01:09 PM

I doubt you'll find out.

396 on a 71 is an irregular. Think I've even read where the SPID says 402, but it's a 396, and vise versa. Perhaps even 1970 trucks with a "396", but it's really a 402....................Fun!

Are you sure it's a 396? If you haven't already, you might search for the part # stamped on the block.

CUDA8U · 09-21-2018, 01:34 PM

Quote:

Originally Posted by 71CHEVYSHORTBED402

I doubt you'll find out.

396 on a 71 is an irregular. Think I've even read where the SPID says 402, but it's a 396, and vise versa. Perhaps even 1970 trucks with a "396", but it's really a 402....................Fun!

Are you sure it's a 396? If you haven't already, you might search for the part # stamped on the block.

i requested more photos including vin,block stamping etc

**71CHEVYSHORTBED402** · 09-21-2018, 02:07 PM

Quote:

Originally Posted by CUDA8U

i requested more photos including vin,block stamping etc

Cool. With a second look, that casting number on the block won't reveal 396 Vs 402. For example, my block is 3969854. Per this it can be a 396, 402 or 454. The block has a date code too.

http://www.chevy-camaro.com/chevy-ca...es.asp?group=1

stsalvage · 09-21-2018, 02:28 PM

Most of you young people where not around when this happened.Over 1000 to 5000 blocks came out of Canada they they had a bad casting.They would not clean up to standard bore 396.Instead of GM scraping the batch they Bord them to 30 over turning them in to 402's

I be leave this happened in 1969.From 1970 you can kinda see that GM wanted to get rid of these motors.

He is a tell tell for that one Reason.

1970 Monte Carlo The new 454 SS came out.They had they 2 versions of the SS options for that car the LS 5 witch was the SS then they had the LS 6 with dealer bolt on alum heads.

Now here is a funny one All SS Monte Carlos Had bucket seats and center console.

New i've come across 5 Monte Carlos with Big block motors in them.Me thinking I had the Hi per 454 I pulled it out checked the numbers

NOOOOOOOOOOOOOpe

it was a 402 truck motor on the block it will say M that means it was ment for truck or car

I saw a few 1971 camro's with 402 and impala with 402.never seen a chevelle or a nova with a 402 kinda strange

**A1971Blazer** · 09-21-2018, 02:33 PM

https://www.hagerty.com/articles-vid...12_HagertyNews

"Fun fact: all 396 engines across the Chevy lineup were actually bored 0.30 over in 1969 due to lax emissions standards for engines over 400 cubic inches.
In the Chevelle, which had built an entire brand around the 396, Chevrolet kept this hush-hush, but in the pickups, where it was known by the L47 RPO code,
it was alternately labeled 396 or 400, confusing gear heads for decades afterwards."

MARKDTN · 09-21-2018, 02:35 PM

Quote:

Originally Posted by stsalvage

Most of you young people where not around when this happened.Over 1000 to 5000 blocks came out of Canada they they had a bad casting.They would not clean up to standard bore 396.Instead of GM scraping the batch they Bord them to 30 over turning them in to 402's

I be leave this happened in 1969.From 1970 you can kinda see that GM wanted to get rid of these motors....

I don't think this is true for many reasons. Here is a much more plausible explanation:

"The 402 was phased in starting in either late December 1969 or January 1970.

The 396 was bored .030 over to 402 to meet emmission standards. The slight increase in size allowed Chevrolet to use the larger motor emmission standards and allowed them to keep the same HP and torque ratings. Starting with cars manufactured in January 1970, higher emission standards were in effect. To address these new standards additional strain was placed on the motor (either via smog pump, lower compression, other emissions equipment or various combinations) so the few extra cubes were needed to make up for the additional power drain.

Since they had invested so much in the SS396 name and mystique, they simply kept the name and gave customers 6 extra cubes for their $$$$. I don't think they would have hurt anything by renaming it SS402, but that's just my opinion..."

https://www.chevelles.com/forums/19-...-vs-402-a.html

**71CHEVYSHORTBED402** · 09-21-2018, 02:49 PM

Quote:

Originally Posted by A1971Blazer

https://www.hagerty.com/articles-vid...12_HagertyNews

"Fun fact: all 396 engines across the Chevy lineup were actually bored 0.30 over in 1969 due to lax emissions standards for engines over 400 cubic inches.
In the Chevelle, which had built an entire brand around the 396, Chevrolet kept this hush-hush, but in the pickups, where it was known by the L47 RPO code,
it was alternately labeled 396 or 400, confusing gear heads for decades afterwards."

weim55 · 09-21-2018, 04:39 PM

[QUOTE=CUDA8U;8348812]I found a 71 396 auto,how many were made?[/QUOTE.

No production number breakdown from GM on these trucks per engine or transmission. After being around this stuff for close to four decades now i'll take a personal guess big block C series production for '71 is somewhere between 5 and 10% .Curious if some others more knowledgeable might toss in their own guess....

Steve weim55 Colorado

**Steeveedee** · 09-21-2018, 07:29 PM

Quote:

Originally Posted by stsalvage

Most of you young people where not around when this happened.Over 1000 to 5000 blocks came out of Canada they they had a bad casting.They would not clean up to standard bore 396.Instead of GM scraping the batch they Bord them to 30 over turning them in to 402's

I be leave this happened in 1969.From 1970 you can kinda see that GM wanted to get rid of these motors.

He is a tell tell for that one Reason.

1970 Monte Carlo The new 454 SS came out.They had they 2 versions of the SS options for that car the LS 5 witch was the SS then they had the LS 6 with dealer bolt on alum heads.

Now here is a funny one All SS Monte Carlos Had bucket seats and center console.

New i've come across 5 Monte Carlos with Big block motors in them.Me thinking I had the Hi per 454 I pulled it out checked the numbers

NOOOOOOOOOOOOOpe

it was a 402 truck motor on the block it will say M that means it was ment for truck or car

I saw a few 1971 camro's with 402 and impala with 402.never seen a chevelle or a nova with a 402 kinda strange

The Novas from '71 and on were only equipped with a 350 for the largest engine as an RPO. Even with the 402 the Camaro and Chevelle still got the 396 badge.

**special-K** · 09-23-2018, 07:05 AM

The short and sweet answer to this question is none. '69 was the last year for 396. I have had '71 big block trucks that said 396 on the SPID. Not sure why with a whole model year between they'd still be doing that. Some of thse trucks were Cheyennes that said CST on the SPID. Way back when I thought I had a rare bird in a '71 Custom Camper/20 that had a 396 and was a CST with no markings other than the SPID that had all the Cheyenne features. Then there are the GMC Cheyennes

. I lucked out with my '72 Sierra. They didn't call it a Cheyenne, they upgraded it to Sierra Grande!

I find it entertaining that there has always been all this conversation over why what when GM took the 396 up to 402 cu when GM did the same for all V8 with the 283 became the 307 and the 327 became the 350, all phased in each year starting in '68 when the new safety and emissions standards were mandated to commence... '68: 283 to 307, '69: 327 to 350, and '70 to 396-402. It's no mystery to me that GM bumped up the cubes a bit and dropped compression, all coinciding with new lower emission standards.

Aluminum heads on the '70 Monte Carlo 454? Never knew about that.

panhead59 · 09-23-2018, 07:54 AM

Tks guys, very interesting. A ton of knowledge here !

**71CHEVYSHORTBED402** · 09-23-2018, 08:43 AM

Makes sense they'd punch out C.I. to meet new emission standards.

California and Govt. trucks led the way in emission standards. For example, the vapor can was required one year earlier (approx.) than the rest of the States. I believe they were mandated for all 1971 models. Coolant expansion tanks are another example. Looks like the 396 was phased out sometime 1969-70. Perhaps 1969 was for Govt. vehicles, Ca. or?

Possible there were 396 inventories left over that would carry onto 1971? I'm on board with Tim, the answer is nope. But why wouldn't there be a real 396 on a 1970? My truck is indication of production flow, they were moving inventory out fast. I believe every part on my truck that's date stamped is April 1971. The build date is May 1971.

On a side, I've read GM kept the "396" label because of recognition. Yeah okay, then why just a few? I suspect pseudo 396 came from the same location(s), build and/or dealer.

I've read they punched out the 402 because they didn't want a SBC (400) with more C.I. than a BBC (396), ha!. Doesn't seem right. But I'll throw a mix into it, just a thought. They had the 400 emblems made before plans for a 402. This explains why 400 emblems are on 402 trucks

Or with additional confusion, a quasi 400 emblem with a quasi 396 block.............Neither one is right

396 to 402 makes up for what 1969-70 to 71? Only emission items I'm aware of for my 71 & 72 are TCS & vapor can. Some 1970 had cans too (e.g., Ca.). Apparently TCS = the HP loss? Some 72 had a smog pump right? Strikes me a smog pump requires more HP than CTS. Dollars to donuts the smog pump was initially required for Ca. and/or govt. trucks.

Great info. in this thread, it's always cool to learn new about these trucks.

TCLARK · 09-24-2018, 01:58 PM

Quote:

Originally Posted by stsalvage

Most of you young people where not around when this happened.Over 1000 to 5000 blocks came out of Canada they they had a bad casting.They would not clean up to standard bore 396.Instead of GM scraping the batch they Bord them to 30 over turning them in to 402's

I be leave this happened in 1969.From 1970 you can kinda see that GM wanted to get rid of these motors.

He is a tell tell for that one Reason.

1970 Monte Carlo The new 454 SS came out.They had they 2 versions of the SS options for that car the LS 5 witch was the SS then they had the LS 6 with dealer bolt on alum heads.

Now here is a funny one All SS Monte Carlos Had bucket seats and center console.

New i've come across 5 Monte Carlos with Big block motors in them.Me thinking I had the Hi per 454 I pulled it out checked the numbers

NOOOOOOOOOOOOOpe

it was a 402 truck motor on the block it will say M that means it was ment for truck or car

I saw a few 1971 camro's with 402 and impala with 402.never seen a chevelle or a nova with a 402 kinda strange

1971 Malibu 400 had a 402.

09-21-2018, 11:49 AM	#1
CUDA8U Registered User Join Date: Apr 2018 Location: EDMONTON Posts: 260	how many 71's were 396/auto? I found a 71 396 auto,how many were made?

09-21-2018, 01:09 PM	#2
71CHEVYSHORTBED402 Senior Member Join Date: Feb 2009 Location: Northern Nevada Posts: 7,333	Re: how many 71's were 396/auto? I doubt you'll find out. 396 on a 71 is an irregular. Think I've even read where the SPID says 402, but it's a 396, and vise versa. Perhaps even 1970 trucks with a "396", but it's really a 402....................Fun! Are you sure it's a 396? If you haven't already, you might search for the part # stamped on the block. __________________ Tony 71 Custom Deluxe, SWB, 2WD, 402, A/C. I developed an assembly kit for restoring the (a) truck from the ground up. My build thread, and more on the assembly kit https://67-72chevytrucks.com/vboard/...d.php?t=730025

09-21-2018, 02:28 PM	#5
stsalvage Scrapper 1 Join Date: Jan 2007 Location: Riverside Calif Posts: 1,649	Re: how many 71's were 396/auto? Most of you young people where not around when this happened.Over 1000 to 5000 blocks came out of Canada they they had a bad casting.They would not clean up to standard bore 396.Instead of GM scraping the batch they Bord them to 30 over turning them in to 402's I be leave this happened in 1969.From 1970 you can kinda see that GM wanted to get rid of these motors. He is a tell tell for that one Reason. 1970 Monte Carlo The new 454 SS came out.They had they 2 versions of the SS options for that car the LS 5 witch was the SS then they had the LS 6 with dealer bolt on alum heads. Now here is a funny one All SS Monte Carlos Had bucket seats and center console. New i've come across 5 Monte Carlos with Big block motors in them.Me thinking I had the Hi per 454 I pulled it out checked the numbers NOOOOOOOOOOOOOpe it was a 402 truck motor on the block it will say M that means it was ment for truck or car I saw a few 1971 camro's with 402 and impala with 402.never seen a chevelle or a nova with a 402 kinda strange

09-21-2018, 02:33 PM	#6
A1971Blazer Senior Member Join Date: Nov 2013 Location: East Tennessee Posts: 2,201	Re: how many 71's were 396/auto? https://www.hagerty.com/articles-vid...12_HagertyNews "Fun fact: all 396 engines across the Chevy lineup were actually bored 0.30 over in 1969 due to lax emissions standards for engines over 400 cubic inches. In the Chevelle, which had built an entire brand around the 396, Chevrolet kept this hush-hush, but in the pickups, where it was known by the L47 RPO code, it was alternately labeled 396 or 400, confusing gear heads for decades afterwards." __________________ 1967 C10 Step side 1968 C10 Step side 1970 Chevrolet K/5 Blazer 1972 Chevrolet K/5 Blazer .............

09-21-2018, 04:39 PM	#9
weim55 Registered User Join Date: Jan 2017 Location: Larkspur, Colorado Posts: 916	Re: how many 71's were 396/auto? [QUOTE=CUDA8U;8348812]I found a 71 396 auto,how many were made?[/QUOTE. No production number breakdown from GM on these trucks per engine or transmission. After being around this stuff for close to four decades now i'll take a personal guess big block C series production for '71 is somewhere between 5 and 10% .Curious if some others more knowledgeable might toss in their own guess.... Steve weim55 Colorado Last edited by weim55; 09-21-2018 at 08:08 PM.

09-23-2018, 07:05 AM	#11
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,851	Re: how many 71's were 396/auto? The short and sweet answer to this question is none. '69 was the last year for 396. I have had '71 big block trucks that said 396 on the SPID. Not sure why with a whole model year between they'd still be doing that. Some of thse trucks were Cheyennes that said CST on the SPID. Way back when I thought I had a rare bird in a '71 Custom Camper/20 that had a 396 and was a CST with no markings other than the SPID that had all the Cheyenne features. Then there are the GMC Cheyennes . I lucked out with my '72 Sierra. They didn't call it a Cheyenne, they upgraded it to Sierra Grande! I find it entertaining that there has always been all this conversation over why what when GM took the 396 up to 402 cu when GM did the same for all V8 with the 283 became the 307 and the 327 became the 350, all phased in each year starting in '68 when the new safety and emissions standards were mandated to commence... '68: 283 to 307, '69: 327 to 350, and '70 to 396-402. It's no mystery to me that GM bumped up the cubes a bit and dropped compression, all coinciding with new lower emission standards. Aluminum heads on the '70 Monte Carlo 454? Never knew about that. __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~ Last edited by special-K; 09-23-2018 at 07:26 AM.

09-23-2018, 07:54 AM	#12
panhead59 Registered User Join Date: Feb 2012 Location: Vinton, Va. Posts: 493	Re: how many 71's were 396/auto? Tks guys, very interesting. A ton of knowledge here ! __________________ "You are not forgotten" USMC 75-79 (Aviation Ordnance Tech- F-4 Phantom) 1959 H-D Panhead. Owned since 1978. Currently with son in Lawton, OK. 1968 Chevy Custom SWB pick up. Fleetside. Lowered 4/6. Totally refurbished. 1966 Pontiac GTO. 4 speed. Saved original 389. Now has slightly built 455 engine. 355 rear gears. Very fun to drive !

09-23-2018, 08:43 AM	#13
71CHEVYSHORTBED402 Senior Member Join Date: Feb 2009 Location: Northern Nevada Posts: 7,333	Re: how many 71's were 396/auto? Makes sense they'd punch out C.I. to meet new emission standards. California and Govt. trucks led the way in emission standards. For example, the vapor can was required one year earlier (approx.) than the rest of the States. I believe they were mandated for all 1971 models. Coolant expansion tanks are another example. Looks like the 396 was phased out sometime 1969-70. Perhaps 1969 was for Govt. vehicles, Ca. or? Possible there were 396 inventories left over that would carry onto 1971? I'm on board with Tim, the answer is nope. But why wouldn't there be a real 396 on a 1970? My truck is indication of production flow, they were moving inventory out fast. I believe every part on my truck that's date stamped is April 1971. The build date is May 1971. On a side, I've read GM kept the "396" label because of recognition. Yeah okay, then why just a few? I suspect pseudo 396 came from the same location(s), build and/or dealer. I've read they punched out the 402 because they didn't want a SBC (400) with more C.I. than a BBC (396), ha!. Doesn't seem right. But I'll throw a mix into it, just a thought. They had the 400 emblems made before plans for a 402. This explains why 400 emblems are on 402 trucks Or with additional confusion, a quasi 400 emblem with a quasi 396 block.............Neither one is right 396 to 402 makes up for what 1969-70 to 71? Only emission items I'm aware of for my 71 & 72 are TCS & vapor can. Some 1970 had cans too (e.g., Ca.). Apparently TCS = the HP loss? Some 72 had a smog pump right? Strikes me a smog pump requires more HP than CTS. Dollars to donuts the smog pump was initially required for Ca. and/or govt. trucks. Great info. in this thread, it's always cool to learn new about these trucks. __________________ Tony 71 Custom Deluxe, SWB, 2WD, 402, A/C. I developed an assembly kit for restoring the (a) truck from the ground up. My build thread, and more on the assembly kit https://67-72chevytrucks.com/vboard/...d.php?t=730025 Last edited by 71CHEVYSHORTBED402; 09-23-2018 at 08:56 AM.



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