402 Engine is what year? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

dave3156 · 02-25-2005, 01:46 AM

Does anybody know what years GM put 402 engines in our trucks? I know they started putting 396 engines in them in 1968. Is there a book or website or can anyone tell me what engines came in 1970 models? Thanks.

**VetteVet** · 02-25-2005, 02:00 AM

[QUOTE=dave3156]Does anybody know what years GM put 402 engines in our trucks?
http://rebuilt.com/Chevrolet_Big_Block_Engines.htm

This site says 68 through 72
Vettevet

dave3156 · 02-25-2005, 02:08 AM

Thanks for the info. In the VIN info on GMC Pauls site they only show a 396 in 1968 with 1968 being the first year for the 396. The engine list stops with 1968 on the GMC Pauls site. Seems from that the earliest a 402 was installed would have been 1969 or later.

dave3156 · 02-25-2005, 03:55 AM

I just found part of the info. On the Chevy Duty website it states that 1970 was the first year for the 402. Then the question follows is, did they offer both a 396 and 402 in 1970?

72402 · 02-25-2005, 10:32 AM

71 was the first production year for the 402.

Longhorn Man · 02-25-2005, 11:32 AM

70 was the first year for the 402.
69 was the last year for the 396
one of the many stories (and the one I believe) is inner buisness politics.
The 400 small block was released in '70, and they couldn't have the big bad big block being smaller than the small block, so they geve them an .030 over hole and made it bigger.

To add to the confusion...the hot rods all still said 396...becouse the engine already earned a respected following.
The option stickers in many trucks still said 396....but the badges all said 400...even though, any vehicle that was a big block in 70 & up, had a 402, 427, or 454.... (not sure on the when abouts on the other two there)

LONGHAIR · 02-25-2005, 11:59 AM

I think this is where my pet peeve of "small block 400" came from.
GM called the 402s "400" for some crazy reason? So somehow there are a lot of people that think you have to specifically say that a 400 is a small block. When in reality all of the 400s are small blocks, the big block is 402. This was all 35 years ago.......why can't they let it go?

Did they ever use 427s in trucks? I mean the auto version not the tall deck truck blocks. They went straight from 402 to 454 didn't they?

BigDave · 02-25-2005, 12:20 PM

This is why I have to explain this in just about every discussion I have with anyone who knows cars but doesn't know our trucks. It's is confusing to those outside the ring.

People see the "400" emblem on the side and assume it's a 400 small block. When I tell them it's really a 402 big block they look at me like I'm lying until I pop the hood and they see those big a$$ heads. Then they're like but wait there is no such thing as a 402 BB because there is only the 396, 427, 454 and I tell them no because they took the 396 and massaged it at the factory for the trucks.

Then I really confuse them by telling them about the 400 small block in the Blazer.

It is never ending. However, it does give me a chance to talk about the trucks a lot.

Longhorn Man · 02-25-2005, 01:59 PM

I don't think there was ever a 427 low deck in a truck, I worded that wrong...I ment any vehicle with a big block....blah blah blah.
Big dave...ALL 396 engines were 402 in 1970 and later vehicles. Not just trucks...chevelles and camaros novas...ect. They were just badged as 396 becouse of the performace record they had...the immage.
But the thing that confuses me, if they called it something smaller for immage, then why did they increase the CID over the 400?

LONGHAIR · 02-25-2005, 05:51 PM

I wasn't suggesting that you were Andy..........I was just asking for my own knowledge.

The story I always heard about them (402) is that there was a flood in some storage place at the foundry and that thousands of those blocks were damaged. They had rust on the cylinder bores...so they were .030 overed and that became the 402. It really doesn't explain why they never went back to 396 later though? I'm not sure that I buy any of the stories I've heard.

I still don't get the badging as 400 though? Why not 402? So the could use the existing badges w/o making a change?
Either way there were no more 396s after '69. From 70 and up they are all 402.

BTW, does anyone know of a set of Aluminum heads for a BBC for sale?

sinister72 · 02-25-2005, 07:55 PM

Well to add to all the confusion,,,here is the story an old chevy dealership mechanic told me years ago! That Gm had a large lot of 396 blocks that had a casting flaw,not bad enough to junk ,but easy to fix with a .030 overbore.These where high performance blocks, so slap a set of passenger car heads on and you get a 402 truck engine and GM saves a ton of $.About every 402 i have seen has blocks stamped high perf and heads stamped,,pass...May be true maynot ,but was a good story 20 years ago.

SLS · 02-25-2005, 08:05 PM

I believe that Chevy kept the "396" badge (after going to 402) because of the reputation of the almighty SS396. Everyone at that point in time knew about the Super Sport 396's.

I too believe was purely an 'image' thing from the factory.

I've heard stories that the blocks were stored outside, and sometimes required an overbore because of surface rust from the elements. I dunno....

dave3156 · 02-25-2005, 08:33 PM

Really interesting about the 402. I was digging through my truck stuff and found a sales brochure from 1970 that lists the following engines available for 1970: 250 six, optional 292 six, 307 V8, 350 V8 and 400 V8(the 402). They even listed it in the sales brochure as a 400. The specs for the 402 are:Bore & stroke 4 1/8 X 3 1/4, Compression Ratio 9.0 to 1, Gross Horsepower 310 @ 4800, Net Horsepower 242@4000, Gross Torque 400 ft lb @3200, Net Torque 350 ft lb @ 3000. I have the specs for all 5 engines if anybody wants them posted.

02-25-2005, 01:46 AM	#1
dave3156 Registered User Join Date: Mar 2004 Location: St. Louis, MO Posts: 336	402 Engine in what year? Does anybody know what years GM put 402 engines in our trucks? I know they started putting 396 engines in them in 1968. Is there a book or website or can anyone tell me what engines came in 1970 models? Thanks. Last edited by dave3156; 02-25-2005 at 01:51 AM.

02-25-2005, 02:00 AM	#2
VetteVet Msgt USAF Ret Join Date: Jan 2005 Location: Kalamazoo, Michigan Posts: 8,714	402 years [QUOTE=dave3156]Does anybody know what years GM put 402 engines in our trucks? http://rebuilt.com/Chevrolet_Big_Block_Engines.htm This site says 68 through 72 Vettevet __________________ VetteVet metallic green 67 stepside 74 corvette convertible 1965 Harley sportster 1995 Harley wide glide Growing old is hell, but it beats the alternative.

02-25-2005, 12:20 PM	#8
BigDave I poop on Ford! Join Date: Apr 2002 Location: Houston Area Posts: 295	This is why I have to explain this in just about every discussion I have with anyone who knows cars but doesn't know our trucks. It's is confusing to those outside the ring. People see the "400" emblem on the side and assume it's a 400 small block. When I tell them it's really a 402 big block they look at me like I'm lying until I pop the hood and they see those big a$$ heads. Then they're like but wait there is no such thing as a 402 BB because there is only the 396, 427, 454 and I tell them no because they took the 396 and massaged it at the factory for the trucks. Then I really confuse them by telling them about the 400 small block in the Blazer. It is never ending. However, it does give me a chance to talk about the trucks a lot. __________________ 1972 Chevy Cheyenne - LWB, factory 402BB 2005 Chevy Suburban LT 2006 Chrysler 300C - SRT8

02-25-2005, 07:55 PM	#11
sinister72 Registered User Join Date: Apr 2002 Location: Bowling Green, kentucky Posts: 182	Well to add to all the confusion,,,here is the story an old chevy dealership mechanic told me years ago! That Gm had a large lot of 396 blocks that had a casting flaw,not bad enough to junk ,but easy to fix with a .030 overbore.These where high performance blocks, so slap a set of passenger car heads on and you get a 402 truck engine and GM saves a ton of $.About every 402 i have seen has blocks stamped high perf and heads stamped,,pass...May be true maynot ,but was a good story 20 years ago. __________________ 72 chevy C-10 swb fleetside,402 BB.700r4,buckets,console.etc. 72 Blazer CST 350,AT, new project 1971 Chevy Nova ,355 SB blow through turbo in works.

02-25-2005, 08:05 PM	#12
SLS Finish the'71..or bust! Join Date: Jun 2003 Location: Nashville, TN. Posts: 441	I believe that Chevy kept the "396" badge (after going to 402) because of the reputation of the almighty SS396. Everyone at that point in time knew about the Super Sport 396's. I too believe was purely an 'image' thing from the factory. I've heard stories that the blocks were stored outside, and sometimes required an overbore because of surface rust from the elements. I dunno.... Last edited by SLS; 02-25-2005 at 08:07 PM.

02-25-2005, 02:08 AM	#3
dave3156 Registered User Join Date: Mar 2004 Location: St. Louis, MO Posts: 336	Thanks for the info. In the VIN info on GMC Pauls site they only show a 396 in 1968 with 1968 being the first year for the 396. The engine list stops with 1968 on the GMC Pauls site. Seems from that the earliest a 402 was installed would have been 1969 or later.

02-25-2005, 03:55 AM	#4
dave3156 Registered User Join Date: Mar 2004 Location: St. Louis, MO Posts: 336	I just found part of the info. On the Chevy Duty website it states that 1970 was the first year for the 402. Then the question follows is, did they offer both a 396 and 402 in 1970?

02-25-2005, 10:32 AM	#5
72402 Registered User Join Date: Nov 2004 Location: Cameron, Oklahoma Posts: 199	71 was the first production year for the 402.

02-25-2005, 11:32 AM	#6
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	70 was the first year for the 402. 69 was the last year for the 396 one of the many stories (and the one I believe) is inner buisness politics. The 400 small block was released in '70, and they couldn't have the big bad big block being smaller than the small block, so they geve them an .030 over hole and made it bigger. To add to the confusion...the hot rods all still said 396...becouse the engine already earned a respected following. The option stickers in many trucks still said 396....but the badges all said 400...even though, any vehicle that was a big block in 70 & up, had a 402, 427, or 454.... (not sure on the when abouts on the other two there)

02-25-2005, 11:59 AM	#7
LONGHAIR just can't cover up my redneck Join Date: May 2004 Location: Columbus OH Posts: 11,414	I think this is where my pet peeve of "small block 400" came from. GM called the 402s "400" for some crazy reason? So somehow there are a lot of people that think you have to specifically say that a 400 is a small block. When in reality all of the 400s are small blocks, the big block is 402. This was all 35 years ago.......why can't they let it go? Did they ever use 427s in trucks? I mean the auto version not the tall deck truck blocks. They went straight from 402 to 454 didn't they?

02-25-2005, 01:59 PM	#9
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	I don't think there was ever a 427 low deck in a truck, I worded that wrong...I ment any vehicle with a big block....blah blah blah. Big dave...ALL 396 engines were 402 in 1970 and later vehicles. Not just trucks...chevelles and camaros novas...ect. They were just badged as 396 becouse of the performace record they had...the immage. But the thing that confuses me, if they called it something smaller for immage, then why did they increase the CID over the 400?

02-25-2005, 05:51 PM	#10
LONGHAIR just can't cover up my redneck Join Date: May 2004 Location: Columbus OH Posts: 11,414	I wasn't suggesting that you were Andy..........I was just asking for my own knowledge. The story I always heard about them (402) is that there was a flood in some storage place at the foundry and that thousands of those blocks were damaged. They had rust on the cylinder bores...so they were .030 overed and that became the 402. It really doesn't explain why they never went back to 396 later though? I'm not sure that I buy any of the stories I've heard. I still don't get the badging as 400 though? Why not 402? So the could use the existing badges w/o making a change? Either way there were no more 396s after '69. From 70 and up they are all 402. BTW, does anyone know of a set of Aluminum heads for a BBC for sale?

02-25-2005, 08:33 PM	#13
dave3156 Registered User Join Date: Mar 2004 Location: St. Louis, MO Posts: 336	Really interesting about the 402. I was digging through my truck stuff and found a sales brochure from 1970 that lists the following engines available for 1970: 250 six, optional 292 six, 307 V8, 350 V8 and 400 V8(the 402). They even listed it in the sales brochure as a 400. The specs for the 402 are:Bore & stroke 4 1/8 X 3 1/4, Compression Ratio 9.0 to 1, Gross Horsepower 310 @ 4800, Net Horsepower 242@4000, Gross Torque 400 ft lb @3200, Net Torque 350 ft lb @ 3000. I have the specs for all 5 engines if anybody wants them posted.



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