70 big block 396 or 402? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

gregbr · 03-25-2002, 04:50 PM

I have a 70 GMC 1500, with a factory big block, numbers match. Is there an easy way to tell if this thing is a 396 or a 402? The glove box says 396, the build sheet says 400, the GMC place says 396, and all the books say 396/402 for that code. Engine is stamped/embossed T1117TBG & 3969854, these numbers are on the build sheet also. Does anyone know the true horsepower, GMC says it's 310HP, but nobody has a air cleaner sticker for that. HELP!!

------------------
Thanks, Greg

51 Chevy Longbed
54 Chevy Panel Truck
70 GMC Shortbed Big Block
88 Chevy K1500 Lifted 6"

Pont · 03-25-2002, 04:57 PM

I show that casting #3969854 being a 400/402. Someone will correct me if I'm wrong but I think that 1969 was the last production year for the actuall 396. Not to say that some of these weren't carried over into 1970 and just renamed as 400 or 402 big blocks.

------------------
67 SWB 4x4 - 396 BB / SM420 4 spd
8" lift / 15x14 Welds & 35X14.5 SSR's
Grants Pass, OR

gregbr · 03-25-2002, 04:59 PM

Sounds like if they carried some over to 70, then I won't know for sure until I rebuild her.

67chevelle · 03-25-2002, 05:40 PM

Greg,

sell it to me for $100 and I'll let you know what it is when I go through it.. No scratch that... I'll give you $150..

LOL

67chevelle

------------------
Current rides:
01 GMC 2500 SB HD CC 4x4 8.1 allison
67 Chevelle drag car
509 CI BBC,TH400
9.850 @ 134.55 mph
1970 C10 2WD PU being rebuilt
1967 El Camino 396, TH400 ( wife's drag car)
Jr. Dragster 5 hp B&S for the kids

http://community.webshots.com/user/mark67chevelle

Longhorn Man · 03-25-2002, 05:46 PM

They were suposedly all 402 in '70. The badges will all say 400, the sticker will say 396, but it is supposed to be a 402 after the last '69 truck.

------------------
'69 G.M.C. 350/350. Trying to clean up the left over damage from the Dope-Smokin-Old-Man
I've been dubbed the Longhorn Freak/Fanatic/Expert, I just hope I can live up to it.
Need to pick up the one ton Longhorn with a PONTIAC 350/350soon.
Thanks every one!

Check out The Longhorn Webite.
If you need a pic posted, E-mail me at longhornmail@yahoo.com
Andy, in Columbus Ohio

**70cst** · 03-25-2002, 05:52 PM

I saw a 71 Burb glove box sticker which was printed 396 as the engine although in reality it was 402BB
Dewayne 70cst

jku72 · 03-25-2002, 06:08 PM

The actual displacement for 70 was 402. many prints including gloveboxes still say 396, and in parts stores, many times I have to say 396, because if I say 402, they girl staring at the computer screen trips off line because there is no listing. There is only a tiny chance that it could really be a 396 instead of 402, production date would be a best indicator. My 402 truck was built in Nov. 1969 and has the 402. Labled in the glove box as a 396, and fender as 400.

------------------
jku
70 C30 CST Longhorn
68k10 burb
69 K5 beater
43 willys GPW
40 Chev coupe
67 catalina

**JDL** · 03-25-2002, 07:19 PM

1970 TBG Truck 402cid 310hors 400trans L-47 10, 20, 30

gregbr · 03-25-2002, 10:37 PM

Thanks for the $150 offer, but I will have to pass. How do you guys find out this info, or is it experience. Thanks for the help. Date produced on the build sheet is 12/5/69, if this adds any info.

------------------
Thanks, Greg

51 Chevy Longbed
54 Chevy Panel Truck
70 GMC Shortbed Big Block
88 Chevy K1500 Lifted 6"

REPO1 · 04-02-2002, 09:35 AM

Where did you find the casting number on the engine?

*Fast68Chevy* · 04-02-2002, 01:41 PM

casting number is on the rear top left or right half of bellhousing ledge

thats a 70 engine, will be a 402, no 402 badges were ever made, lists as 396 through RPO code, and 400 through GM, it was a trick against insurance companies trying to end the muscle car era, HP engines, long story...

------------------
Randy- Lincoln, IL
randy@ccaonline.com
-71/C-10(thx teeitup and crews!)350 4+4/CH465(thx 71Chev, GMCPaul, and CPNE)longfleet bed(thnx meathead95)!very apart and not driveable still.....
-'84 Z28 H.O. 305 L69 700R4 GT4 3.73
- 1984 Firebird SE 2.8L T-5 GT4 3.73
-1981 Cutlass Supreme, dunno what im gonna do with it yet...
-79 G20 pass van, 350/th350/10bolt
*Paint is overrated
© RSS Enterprises 2000

**Desert Rat** · 04-02-2002, 02:02 PM

I love this topic,especially when i go to the auto part stores,most of the motors im running right now are 402's.I had a 70 Burban that had 400 emblems,396 on the sticker in glovebox,but engine was actually a 402,didnt the factory screw up and bore all the 396 .030 over?thought thats what it was,oh well at the part stores and books the motor is knows as a 400-4bbl,402,most any 396 external parts fit with the exception of i think from 69 has the large spark plugs and 70 the went to the small one,but i could be off.mentally i am so my info could be.

**Desert Rat** · 04-02-2002, 02:05 PM

The factory Big Block 68 Burb i had,had been decked at one point,so all codes were gone upon pulling motor i realized someone replaced the block at one time it was a 71 402 block,but still had the 68 heads and intake,that was a disapointment.but now im selling all the 396/402's and sticking to 454's.motor wise bigger is better.

*Fast68Chevy* · 04-02-2002, 02:12 PM

uhm they bored them on purpose, thats a big accident, i mean then pistons would have to be made lol,
there are rumors that there was a fire or something in one of the plants where a bunch of 396 were and the water form oputting out the fire got in the motors and rusted the cylinder so they had to overbore them and then they got their 402 that way, but i havent seen proof of that happening as of yet.

the only bad thing about 454 now is that all you can fin od them are the less rated smogger ones..

------------------
Randy- Lincoln, IL
randy@ccaonline.com
-71/C-10(thx teeitup and crews!)350 4+4/CH465(thx 71Chev, GMCPaul, and CPNE)longfleet bed(thnx meathead95)!very apart and not driveable still.....
-'84 Z28 H.O. 305 L69 700R4 GT4 3.73
- 1984 Firebird SE 2.8L T-5 GT4 3.73
-1981 Cutlass Supreme, dunno what im gonna do with it yet...
-79 G20 pass van, 350/th350/10bolt
*Paint is overrated
© RSS Enterprises 2000

[This message has been edited by Fast68Chevy (edited April 02, 2002).]

gregsplace · 04-02-2002, 05:40 PM

I dont buy the fire theory much. There would have have to been 1000's of blocks in that plant to justify machining, and making new badges etc,etc..... but who knows. I'm kidda thinking like Micah on unloading all the 396's and 402's I have too, and sticking with 454's. They are a lot cheaper to rebuild for me.....Greg

------------------
67 3/4 4x4 402,a/t,HEI,edelbrock 1411

87 Burb-454!
86 z-28
71 1/2 2wh project
69 swb stepside project, soon to have 396/400th
67 swb fleet project
too many projects!!!
99,HD,XL1200c sportster
buy and sell 67 to 72 parts, near Colwich Ks

gregbr · 04-02-2002, 10:02 PM

How much do ya'll want for those old 396/402 engines? I kinda like mine.

------------------
Thanks, Greg

51 Chevy Longbed
54 Chevy Panel Truck
70 GMC Shortbed Big Block
88 Chevy K1500 Lifted 6"

03-25-2002, 04:50 PM	#1
gregbr Senoir Member Join Date: Mar 2002 Location: Rock Hill, SC USA Posts: 1,214	70 big block 396 or 402? I have a 70 GMC 1500, with a factory big block, numbers match. Is there an easy way to tell if this thing is a 396 or a 402? The glove box says 396, the build sheet says 400, the GMC place says 396, and all the books say 396/402 for that code. Engine is stamped/embossed T1117TBG & 3969854, these numbers are on the build sheet also. Does anyone know the true horsepower, GMC says it's 310HP, but nobody has a air cleaner sticker for that. HELP!! ------------------ Thanks, Greg 51 Chevy Longbed 54 Chevy Panel Truck 70 GMC Shortbed Big Block 88 Chevy K1500 Lifted 6" __________________ 67 Chevy, Small back glass, Factory 4WD, Factory Shortbed, Factory V8, Lifted 4" 70 GMC Sierra Grande, Factory Shortbed, Factory 402/400 turbo, Super Custom Interior. Numbers matching with SPID & Build Sheet. 68K Original Miles. Restored 2010 70 GMC Restoration Pictures http://67-72chevytrucks.com/gallery/...00&ppuser=4424

03-25-2002, 04:57 PM	#2
Pont I need another Barley Pop Join Date: Feb 2001 Location: Grants Pass, OR Posts: 1,629	I show that casting #3969854 being a 400/402. Someone will correct me if I'm wrong but I think that 1969 was the last production year for the actuall 396. Not to say that some of these weren't carried over into 1970 and just renamed as 400 or 402 big blocks. ------------------ 67 SWB 4x4 - 396 BB / SM420 4 spd 8" lift / 15x14 Welds & 35X14.5 SSR's Grants Pass, OR __________________ 67 Short Fleet 4x4 04 Honda CRF450R 89 Toyota 4-Runner 34 Ford 2 door sedan - Long term project ---------------------------------------------- There is a very fine line between "hobby" and "mental illness"

03-25-2002, 05:40 PM	#4
67chevelle drag racer Join Date: Nov 2001 Location: Meridian Idaho Posts: 127	Greg, sell it to me for $100 and I'll let you know what it is when I go through it.. No scratch that... I'll give you $150.. LOL 67chevelle ------------------ Current rides: 01 GMC 2500 SB HD CC 4x4 8.1 allison 67 Chevelle drag car 509 CI BBC,TH400 9.850 @ 134.55 mph 1970 C10 2WD PU being rebuilt 1967 El Camino 396, TH400 ( wife's drag car) Jr. Dragster 5 hp B&S for the kids http://community.webshots.com/user/mark67chevelle __________________ Current rides: 01 GMC 2500 SB HD CC 4x4 8.1 allison 67 Chevelle drag car 516 CI BBC,TH400 9.777 @ 138.4 mph 1970 C10 2WD PU being rebuilt 1967 El Camino 502, TH400 ( wife's drag car) Jr. Dragster 5 hp B&S for the kids

03-25-2002, 05:52 PM	#6
70cst Senior Member Join Date: Feb 2001 Location: New Madison, Ohio Posts: 21,373	I saw a 71 Burb glove box sticker which was printed 396 as the engine although in reality it was 402BB Dewayne 70cst __________________ A husband can be right...or...A husband can be happy. 67-72 Chevy and GMC Trucks...The Classic Truck for the Classic Folk. 1970 CST Two tone green, 402BB, 400 Automatic, Tach, Buckets, AC, AM-FM, Tilt, GM CB, GM 8 Tract, LWB, etc JOHN 17:3...The better side of "LIFE" Remember: Everyday is a good day...Some are just gooder!

03-25-2002, 06:08 PM	#7
jku72 Registered User Join Date: Jan 2002 Location: cornville, maine Posts: 659	The actual displacement for 70 was 402. many prints including gloveboxes still say 396, and in parts stores, many times I have to say 396, because if I say 402, they girl staring at the computer screen trips off line because there is no listing. There is only a tiny chance that it could really be a 396 instead of 402, production date would be a best indicator. My 402 truck was built in Nov. 1969 and has the 402. Labled in the glove box as a 396, and fender as 400. ------------------ jku 70 C30 CST Longhorn 68k10 burb 69 K5 beater 43 willys GPW 40 Chev coupe 67 catalina __________________ jku Cornville, Maine 68 C10 burb 42 Willys MB 46 Dodge WF-32 1.5 ton 53 & 56 Olds' 60 Cadillac 22 Dodge Brothers

03-25-2002, 04:59 PM	#3
gregbr Senoir Member Join Date: Mar 2002 Location: Rock Hill, SC USA Posts: 1,214	Sounds like if they carried some over to 70, then I won't know for sure until I rebuild her. __________________ 67 Chevy, Small back glass, Factory 4WD, Factory Shortbed, Factory V8, Lifted 4" 70 GMC Sierra Grande, Factory Shortbed, Factory 402/400 turbo, Super Custom Interior. Numbers matching with SPID & Build Sheet. 68K Original Miles. Restored 2010 70 GMC Restoration Pictures http://67-72chevytrucks.com/gallery/...00&ppuser=4424

03-25-2002, 05:46 PM	#5
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	They were suposedly all 402 in '70. The badges will all say 400, the sticker will say 396, but it is supposed to be a 402 after the last '69 truck. ------------------ '69 G.M.C. 350/350. Trying to clean up the left over damage from the Dope-Smokin-Old-Man I've been dubbed the Longhorn Freak/Fanatic/Expert, I just hope I can live up to it. Need to pick up the one ton Longhorn with a PONTIAC 350/350soon. Thanks every one! Check out The Longhorn Webite. If you need a pic posted, E-mail me at longhornmail@yahoo.com Andy, in Columbus Ohio

03-25-2002, 07:19 PM	#8
JDL Senior Member Join Date: Sep 2000 Location: Agency IA. Posts: 1,848	1970 TBG Truck 402cid 310hors 400trans L-47 10, 20, 30 __________________ 72 Chevy short step side with 454 air and tilt. 72 nova project car 63 chevy II drag car Agency Iowa

03-25-2002, 10:37 PM	#9
gregbr Senoir Member Join Date: Mar 2002 Location: Rock Hill, SC USA Posts: 1,214	Thanks for the $150 offer, but I will have to pass. How do you guys find out this info, or is it experience. Thanks for the help. Date produced on the build sheet is 12/5/69, if this adds any info. ------------------ Thanks, Greg 51 Chevy Longbed 54 Chevy Panel Truck 70 GMC Shortbed Big Block 88 Chevy K1500 Lifted 6" __________________ 67 Chevy, Small back glass, Factory 4WD, Factory Shortbed, Factory V8, Lifted 4" 70 GMC Sierra Grande, Factory Shortbed, Factory 402/400 turbo, Super Custom Interior. Numbers matching with SPID & Build Sheet. 68K Original Miles. Restored 2010 70 GMC Restoration Pictures http://67-72chevytrucks.com/gallery/...00&ppuser=4424

04-02-2002, 09:35 AM	#10
REPO1 Shortbox wanna-be. Join Date: Mar 2002 Location: Fort St.John, British Columbia, Canada Posts: 773	Where did you find the casting number on the engine? __________________ 1970 Chevy C20 Custom Camper 402BB Turbo 400 trans. (Slowly becoming a '70 shortbox 1/2 ton) '71 Camaro SS 402/T400 resto '97 Z28 (11.41@127MPH)

04-02-2002, 01:41 PM	#11
Fast68Chevy Account Suspended Join Date: May 2000 Location: IL Posts: 0	casting number is on the rear top left or right half of bellhousing ledge thats a 70 engine, will be a 402, no 402 badges were ever made, lists as 396 through RPO code, and 400 through GM, it was a trick against insurance companies trying to end the muscle car era, HP engines, long story... ------------------ Randy- Lincoln, IL randy@ccaonline.com -71/C-10(thx teeitup and crews!)350 4+4/CH465(thx 71Chev, GMCPaul, and CPNE)longfleet bed(thnx meathead95)!very apart and not driveable still..... -'84 Z28 H.O. 305 L69 700R4 GT4 3.73 - 1984 Firebird SE 2.8L T-5 GT4 3.73 -1981 Cutlass Supreme, dunno what im gonna do with it yet... -79 G20 pass van, 350/th350/10bolt *Paint is overrated © RSS Enterprises 2000

04-02-2002, 02:02 PM	#12
Desert Rat Senior Member Join Date: Dec 1999 Location: Darrington, Washington Posts: 3,963	I love this topic,especially when i go to the auto part stores,most of the motors im running right now are 402's.I had a 70 Burban that had 400 emblems,396 on the sticker in glovebox,but engine was actually a 402,didnt the factory screw up and bore all the 396 .030 over?thought thats what it was,oh well at the part stores and books the motor is knows as a 400-4bbl,402,most any 396 external parts fit with the exception of i think from 69 has the large spark plugs and 70 the went to the small one,but i could be off.mentally i am so my info could be.

04-02-2002, 02:05 PM	#13
Desert Rat Senior Member Join Date: Dec 1999 Location: Darrington, Washington Posts: 3,963	The factory Big Block 68 Burb i had,had been decked at one point,so all codes were gone upon pulling motor i realized someone replaced the block at one time it was a 71 402 block,but still had the 68 heads and intake,that was a disapointment.but now im selling all the 396/402's and sticking to 454's.motor wise bigger is better.

04-02-2002, 02:12 PM	#14
Fast68Chevy Account Suspended Join Date: May 2000 Location: IL Posts: 0	uhm they bored them on purpose, thats a big accident, i mean then pistons would have to be made lol, there are rumors that there was a fire or something in one of the plants where a bunch of 396 were and the water form oputting out the fire got in the motors and rusted the cylinder so they had to overbore them and then they got their 402 that way, but i havent seen proof of that happening as of yet. the only bad thing about 454 now is that all you can fin od them are the less rated smogger ones.. ------------------ Randy- Lincoln, IL randy@ccaonline.com -71/C-10(thx teeitup and crews!)350 4+4/CH465(thx 71Chev, GMCPaul, and CPNE)longfleet bed(thnx meathead95)!very apart and not driveable still..... -'84 Z28 H.O. 305 L69 700R4 GT4 3.73 - 1984 Firebird SE 2.8L T-5 GT4 3.73 -1981 Cutlass Supreme, dunno what im gonna do with it yet... -79 G20 pass van, 350/th350/10bolt *Paint is overrated © RSS Enterprises 2000 [This message has been edited by Fast68Chevy (edited April 02, 2002).]

04-02-2002, 05:40 PM	#15
gregsplace Senior Member Join Date: Dec 2000 Location: Colwich,Kansas Posts: 713	I dont buy the fire theory much. There would have have to been 1000's of blocks in that plant to justify machining, and making new badges etc,etc..... but who knows. I'm kidda thinking like Micah on unloading all the 396's and 402's I have too, and sticking with 454's. They are a lot cheaper to rebuild for me.....Greg ------------------ 67 3/4 4x4 402,a/t,HEI,edelbrock 1411 87 Burb-454! 86 z-28 71 1/2 2wh project 69 swb stepside project, soon to have 396/400th 67 swb fleet project too many projects!!! 99,HD,XL1200c sportster buy and sell 67 to 72 parts, near Colwich Ks __________________ 67 3/4 4x4 402,a/t,flat bed 98 GMC Sierra swb daily driver 87 burb parting out. 68 1/2 chevy, 350/350, 71 gmc frame, kid's beater 69 1ton 396-4sp, dump 69 swb stepside 396/400th current frameup 67 swb 454/400th rebuilding now, oldest boy just rolled it 99,HD, Road King Classic Colwich Ks



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04-02-2002, 10:02 PM	#16
gregbr Senoir Member Join Date: Mar 2002 Location: Rock Hill, SC USA Posts: 1,214	How much do ya'll want for those old 396/402 engines? I kinda like mine. ------------------ Thanks, Greg 51 Chevy Longbed 54 Chevy Panel Truck 70 GMC Shortbed Big Block 88 Chevy K1500 Lifted 6" __________________ 67 Chevy, Small back glass, Factory 4WD, Factory Shortbed, Factory V8, Lifted 4" 70 GMC Sierra Grande, Factory Shortbed, Factory 402/400 turbo, Super Custom Interior. Numbers matching with SPID & Build Sheet. 68K Original Miles. Restored 2010 70 GMC Restoration Pictures http://67-72chevytrucks.com/gallery/...00&ppuser=4424

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