Factory big block trucks? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Barnfind46 · 02-11-2016, 08:31 PM

I have a quick question.My dad bought a 67' or 68' C-10 when I was a kid back in 1973.The truck was six or seven years old so I don't think it had been messed with much.It had a big block 396 with 400 auto.Did they put the 396 in trucks or was this a swap? I later learned to drive in it and started maintaining it. (changing alt,replacing rocker arms and stuff like that)It was the ever popular orange/red with white top CST. I bought a 68' C-20 in the same color 14 years ago that was a painted bumpers no trim truck.Every time I climb in it I am 16 years old again!

**68350** · 02-11-2016, 08:57 PM

The 396 first appeared in trucks in 1968. In 1970 it changed to the 402. Then the 454 in 73+

Barnfind46 · 02-11-2016, 09:03 PM

So it was a 68'. I remember that it had a two barrel carb. I don't remember if it had a carb adapter but I bet it did.

davepl · 02-11-2016, 10:42 PM

In the passenger cars there was a 396 2bbl offered in 265hp trim. Our 396 was rated at 310hp with a four-barrel.

It's very similar to the 396/325 but with a flat intake and slightly tamer cam.

I'm not aware of any big block 2-barrels in the trucks but I don't know my 68s very well!

**70cst** · 02-11-2016, 10:55 PM

Quote:

Originally Posted by davepl

In the passenger cars there was a 396 2bbl offered in 265hp trim. Our 396 was rated at 310hp with a four-barrel.

It's very similar to the 396/325 but with a flat intake and slightly tamer cam.

I'm not aware of any big block 2-barrels in the trucks but I don't know my 68s very well!

I would agree ... all the 396 were four-barrels ...

**70cst** · 02-11-2016, 10:57 PM

Quote:

Originally Posted by 68350

The 396 first appeared in trucks in 1968. In 1970 it changed to the 402. Then the 454 in 73+

Agreed - although one might find the term 396 typed on the SPID in 70 model trucks yet factually it was a 402

**70cst** · 02-11-2016, 10:58 PM

By the way Barnfind46 ...

to the forums and

from Ohio

**68350** · 02-11-2016, 11:53 PM

I could swear I remember a black 69 chevy or gmc posted on here before that was a Canadian truck built with a 396 2 bbl

Barnfind46 · 02-12-2016, 12:03 AM

Thanks for the welcome 70cst. Dad's 68' had chrome reverse wheels with moon hubcaps and raised letter tires. It had a camper shell with smoked bubble windows. You gotta love the 70's.

**70cst** · 02-12-2016, 12:04 AM

Quote:

Originally Posted by Barnfind46

Thanks for the welcome 70cst. Dad's 68' had chrome reverse wheels with moon hubcaps and raised letter tires. It had a camper shell with smoked bubble windows. You gotta love the 70's.

I do I do luv the 70's

**70cst** · 02-12-2016, 12:05 AM

Quote:

Originally Posted by 68350

I could swear I remember a black 69 chevy or gmc posted on here before that was a Canadian truck built with a 396 2 bbl

That's possible - I just can't ever recall seeing a 2bbl 396.
Maybe we can get some other inputs

**68350** · 02-12-2016, 12:52 AM

The only reason I remember is it was so odd to me. Might Ave to do some digging in big block threads or black truck threads

**68350** · 02-12-2016, 01:48 AM

http://67-72chevytrucks.com/vboard/s...d.php?t=403113

Here is the thread on 396 2 bbl pickups I was referring to

SS Tim · 02-12-2016, 02:01 AM

In 68 Chevy offered as optional V-8s both the L66 396 2bbl and the L47 396 4bbl engines rated 275 hp @4400 RPM gross and 310 hp @4800 RPM gross respectively in pickups. Here is a 68 Longhorn 20's.

**tll74** · 02-12-2016, 02:53 AM

subscribed...

**70cst** · 02-12-2016, 10:06 AM

Quote:

Originally Posted by 68350

http://67-72chevytrucks.com/vboard/s...d.php?t=403113

Here is the thread on 396 2 bbl pickups I was referring to

Thanks - in my old age I learned something new

**70cst** · 02-12-2016, 10:08 AM

Quote:

Originally Posted by SS Tim

In 68 Chevy offered as optional V-8s both the L66 396 2bbl and the L47 396 4bbl engines rated 275 hp @4400 RPM gross and 310 hp @4800 RPM gross respectively in pickups. Here is a 68 Longhorn 20's.

Thanks Tim ... its amazing there always something new to learn about these trucks

northerngmc · 02-12-2016, 02:00 PM

My 68 C20 with a factory 396 was an L66. Previous owner swapped it over to a 4 barrel.

davepl · 02-12-2016, 02:10 PM

I'm surprised there's such a horsepower difference (265 vs 310/325). If you look at the base 350 in 1969, it was rated at 250hp with a 2bbl or 255hp with a 4bbl, but for some reason the 396 jumps almost 50hp?

In other forums online they state the cam is the same between the 265 and the 325, but pretty weird that you'd get 60hp from a 4-bbl. Maybe the 2bbl truly taps out on a 350 and just isn't big enough for the 396? Odd.

northerngmc · 02-12-2016, 02:47 PM

Ok, I just googled 1968 L66 and found this BC licence plate on eBay.

I had to buy it......

Mike C · 02-15-2016, 09:07 AM

My guess is you are seeing the limits of 350 cfm on a 400 cubic inch motor. The 2 bbl engine is just out of fuel at a much lower rpm than the 4 bbl motor. And based on GM's ratings, to the tune of 50 hp.

**Steeveedee** · 02-15-2016, 04:51 PM

I've seen plenty of big blocks with 2 barrel carbs, I worked for a Chevy dealer on and off from 1970-1972. I'd suspect that the cam would be different between the two barrel and 4 barrel, but have no proof. I've even seen 421 Pontiacs with a 2 barrel. Our body shop manager had a '68 Star Chief that got 20 MPG on the open road with that setup. Beasts like that had tons of torque, and even the big cars had tall axles.

dubds10 · 02-15-2016, 05:00 PM

Quote:

Originally Posted by northerngmc

Ok, I just googled 1968 L66 and found this BC licence plate on eBay.

I had to buy it......

That's Ontario not BC. How dare you degrade our BC name haha

northerngmc · 02-15-2016, 07:27 PM

Quote:

Originally Posted by dubds10

That's Ontario not BC. How dare you degrade our BC name haha

Not sure how that happened..... I noticed later and the edit button seems to be missing.

davepl · 02-15-2016, 07:46 PM

Quote:

Originally Posted by Mike C

My guess is you are seeing the limits of 350 cfm on a 400 cubic inch motor. The 2 bbl engine is just out of fuel at a much lower rpm than the 4 bbl motor. And based on GM's ratings, to the tune of 50 hp.

That was my guess as well. The 350 just squeaks by with the 2bbl, but the 396 taps it out.

I bet that's some seriously crisp throttle response though!

02-11-2016, 08:31 PM	#1
Barnfind46 Registered User Join Date: Aug 2014 Location: Mena,Arkansas Posts: 485	Factory big block trucks? I have a quick question.My dad bought a 67' or 68' C-10 when I was a kid back in 1973.The truck was six or seven years old so I don't think it had been messed with much.It had a big block 396 with 400 auto.Did they put the 396 in trucks or was this a swap? I later learned to drive in it and started maintaining it. (changing alt,replacing rocker arms and stuff like that)It was the ever popular orange/red with white top CST. I bought a 68' C-20 in the same color 14 years ago that was a painted bumpers no trim truck.Every time I climb in it I am 16 years old again!

02-11-2016, 08:57 PM	#2
68350 Senior Member Join Date: Jan 2002 Location: Williston, ND Posts: 2,999	Re: Factory big block trucks? The 396 first appeared in trucks in 1968. In 1970 it changed to the 402. Then the 454 in 73+ __________________ 68 Chevy CST/10, 50th Anniversary, 327/th400, 373 posi, buckets 68 GMC Shortbox Stepside, 402/th400, Tilt, Tach, Bucket Seats, 3.08 Positraction 69 Chevy Camaro SS, 383, 4 speed, positraction 70 Chevy El Camino SS396, Triple Black, 454/th400, Tach 70 Chevy Shortbox Stepside 4x4, 350/th350, Tilt, Tach, Cab Lights, Bumper Guards, Tow Hooks 70 Chevy 3/4 Longbox, 350/auto, 70k, SURVIVOR 71 Chevy Blazer, CST, 350/auto 71 GMC Sierra K2500, 454, 4 speed, 4.10 posi, 37s 71 Custom/30, Open Road, 350/th400, tilt 72 Chevy Shortbox Fleetside, 496 Stroker/th400, Tilt, Tach, Bucket Seats, 3.42 Posi 72 GMC Sierra Grande 2500. 427/th400, tilt, a/c, tool and stowage, buckets/console, 3.54 posi

02-11-2016, 09:03 PM	#3
Barnfind46 Registered User Join Date: Aug 2014 Location: Mena,Arkansas Posts: 485	Re: Factory big block trucks? So it was a 68'. I remember that it had a two barrel carb. I don't remember if it had a carb adapter but I bet it did.

02-11-2016, 10:42 PM	#4
davepl Registered User Join Date: Aug 2006 Location: Redmond, WA Posts: 6,332	Re: Factory big block trucks? In the passenger cars there was a 396 2bbl offered in 265hp trim. Our 396 was rated at 310hp with a four-barrel. It's very similar to the 396/325 but with a flat intake and slightly tamer cam. I'm not aware of any big block 2-barrels in the trucks but I don't know my 68s very well! __________________ 1970 GMC Sierra Grande Custom Camper - Built, not Bought 1969 Pontiac 2+2 427/390 4-speed Coupe 1969 Pontiac 2+2 427/390 4-speed Convertible

02-11-2016, 10:58 PM	#7
70cst Senior Member Join Date: Feb 2001 Location: New Madison, Ohio Posts: 21,358	Re: Factory big block trucks? By the way Barnfind46 ... to the forums and from Ohio __________________ 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!

02-11-2016, 11:53 PM	#8
68350 Senior Member Join Date: Jan 2002 Location: Williston, ND Posts: 2,999	Re: Factory big block trucks? I could swear I remember a black 69 chevy or gmc posted on here before that was a Canadian truck built with a 396 2 bbl __________________ 68 Chevy CST/10, 50th Anniversary, 327/th400, 373 posi, buckets 68 GMC Shortbox Stepside, 402/th400, Tilt, Tach, Bucket Seats, 3.08 Positraction 69 Chevy Camaro SS, 383, 4 speed, positraction 70 Chevy El Camino SS396, Triple Black, 454/th400, Tach 70 Chevy Shortbox Stepside 4x4, 350/th350, Tilt, Tach, Cab Lights, Bumper Guards, Tow Hooks 70 Chevy 3/4 Longbox, 350/auto, 70k, SURVIVOR 71 Chevy Blazer, CST, 350/auto 71 GMC Sierra K2500, 454, 4 speed, 4.10 posi, 37s 71 Custom/30, Open Road, 350/th400, tilt 72 Chevy Shortbox Fleetside, 496 Stroker/th400, Tilt, Tach, Bucket Seats, 3.42 Posi 72 GMC Sierra Grande 2500. 427/th400, tilt, a/c, tool and stowage, buckets/console, 3.54 posi

02-12-2016, 12:03 AM	#9
Barnfind46 Registered User Join Date: Aug 2014 Location: Mena,Arkansas Posts: 485	Re: Factory big block trucks? Thanks for the welcome 70cst. Dad's 68' had chrome reverse wheels with moon hubcaps and raised letter tires. It had a camper shell with smoked bubble windows. You gotta love the 70's.

02-12-2016, 12:52 AM	#12
68350 Senior Member Join Date: Jan 2002 Location: Williston, ND Posts: 2,999	Re: Factory big block trucks? The only reason I remember is it was so odd to me. Might Ave to do some digging in big block threads or black truck threads __________________ 68 Chevy CST/10, 50th Anniversary, 327/th400, 373 posi, buckets 68 GMC Shortbox Stepside, 402/th400, Tilt, Tach, Bucket Seats, 3.08 Positraction 69 Chevy Camaro SS, 383, 4 speed, positraction 70 Chevy El Camino SS396, Triple Black, 454/th400, Tach 70 Chevy Shortbox Stepside 4x4, 350/th350, Tilt, Tach, Cab Lights, Bumper Guards, Tow Hooks 70 Chevy 3/4 Longbox, 350/auto, 70k, SURVIVOR 71 Chevy Blazer, CST, 350/auto 71 GMC Sierra K2500, 454, 4 speed, 4.10 posi, 37s 71 Custom/30, Open Road, 350/th400, tilt 72 Chevy Shortbox Fleetside, 496 Stroker/th400, Tilt, Tach, Bucket Seats, 3.42 Posi 72 GMC Sierra Grande 2500. 427/th400, tilt, a/c, tool and stowage, buckets/console, 3.54 posi

02-12-2016, 01:48 AM	#13
68350 Senior Member Join Date: Jan 2002 Location: Williston, ND Posts: 2,999	Re: Factory big block trucks? http://67-72chevytrucks.com/vboard/s...d.php?t=403113 Here is the thread on 396 2 bbl pickups I was referring to __________________ 68 Chevy CST/10, 50th Anniversary, 327/th400, 373 posi, buckets 68 GMC Shortbox Stepside, 402/th400, Tilt, Tach, Bucket Seats, 3.08 Positraction 69 Chevy Camaro SS, 383, 4 speed, positraction 70 Chevy El Camino SS396, Triple Black, 454/th400, Tach 70 Chevy Shortbox Stepside 4x4, 350/th350, Tilt, Tach, Cab Lights, Bumper Guards, Tow Hooks 70 Chevy 3/4 Longbox, 350/auto, 70k, SURVIVOR 71 Chevy Blazer, CST, 350/auto 71 GMC Sierra K2500, 454, 4 speed, 4.10 posi, 37s 71 Custom/30, Open Road, 350/th400, tilt 72 Chevy Shortbox Fleetside, 496 Stroker/th400, Tilt, Tach, Bucket Seats, 3.42 Posi 72 GMC Sierra Grande 2500. 427/th400, tilt, a/c, tool and stowage, buckets/console, 3.54 posi

02-12-2016, 02:01 AM	#14
SS Tim Registered User Join Date: Aug 2010 Location: Edwards, CA Posts: 7,503	Re: Factory big block trucks? In 68 Chevy offered as optional V-8s both the L66 396 2bbl and the L47 396 4bbl engines rated 275 hp @4400 RPM gross and 310 hp @4800 RPM gross respectively in pickups. Here is a 68 Longhorn 20's. Attached Images __________________ Thanks, Tim * VIN/Model Decoders * Power Team Charts (engine/transmission/gear ratio) * Post Your Pickup SPID Blazer SPID Suburban/Panel SPID * RTFM ... Read The Factory Manuals... download 'em here Highlanders Do you have a 1972 Plaid Pickup? Plaid Blazer ** Plaid Suburban

02-12-2016, 02:53 AM	#15
tll74 "Junkyard Dog" Join Date: Jan 2008 Location: Springfield Oregon Posts: 2,527	Re: Factory big block trucks? subscribed... __________________ 72 C-10 Cheyenne Super LWB, Vortec 427,TH700, 3.73 posi, tach, tilt, AM-FM,Frame off in process. http://s289.photobucket.com/albums/l...t=7eae161e.pbw 88 Monte Carlo SS bought new only 10k miles. 73 Chevelle SS 454 had since high school. 74 Camaro Z28 350 AT numbers matching, Black on Black. 73 El Camino SS 350 4sp. 70 Chevelle SS 396 4sp, number matching with LS6 454 69 Chevy C30 Car Hauler 86 K20 383 4sp 4" lift frame off restoration. http://s289.photobucket.com/albums/l...t=1b1082d3.pbw

02-12-2016, 02:00 PM	#18
northerngmc Registered User Join Date: Jan 2004 Location: Whitehorse YK Canada Posts: 2,651	Re: Factory big block trucks? My 68 C20 with a factory 396 was an L66. Previous owner swapped it over to a 4 barrel. __________________ Blaine 59 GMC 9314 a.k.a. Whoopee 68 C20 50th Anniversary a.k.a. The Rat http://www.flickr.com/photos/northerngmc/ http://www.members.tripod.com/P-wee/index_032.htm 1.61803 is one H of a lot better than 3.14159, no really it is!

02-12-2016, 02:10 PM	#19
davepl Registered User Join Date: Aug 2006 Location: Redmond, WA Posts: 6,332	Re: Factory big block trucks? I'm surprised there's such a horsepower difference (265 vs 310/325). If you look at the base 350 in 1969, it was rated at 250hp with a 2bbl or 255hp with a 4bbl, but for some reason the 396 jumps almost 50hp? In other forums online they state the cam is the same between the 265 and the 325, but pretty weird that you'd get 60hp from a 4-bbl. Maybe the 2bbl truly taps out on a 350 and just isn't big enough for the 396? Odd. __________________ 1970 GMC Sierra Grande Custom Camper - Built, not Bought 1969 Pontiac 2+2 427/390 4-speed Coupe 1969 Pontiac 2+2 427/390 4-speed Convertible

02-12-2016, 02:47 PM	#20
northerngmc Registered User Join Date: Jan 2004 Location: Whitehorse YK Canada Posts: 2,651	Re: Factory big block trucks? Ok, I just googled 1968 L66 and found this BC licence plate on eBay. I had to buy it...... __________________ Blaine 59 GMC 9314 a.k.a. Whoopee 68 C20 50th Anniversary a.k.a. The Rat http://www.flickr.com/photos/northerngmc/ http://www.members.tripod.com/P-wee/index_032.htm 1.61803 is one H of a lot better than 3.14159, no really it is!

02-15-2016, 09:07 AM	#21
Mike C Registered User Join Date: Dec 1999 Location: Austin, TX, USA Posts: 7,714	Re: Factory big block trucks? My guess is you are seeing the limits of 350 cfm on a 400 cubic inch motor. The 2 bbl engine is just out of fuel at a much lower rpm than the 4 bbl motor. And based on GM's ratings, to the tune of 50 hp. __________________ 44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax



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02-15-2016, 04:51 PM	#22
Steeveedee Who Changed This? Join Date: Jan 2013 Location: Simi Valley, CA Posts: 10,165	Re: Factory big block trucks? I've seen plenty of big blocks with 2 barrel carbs, I worked for a Chevy dealer on and off from 1970-1972. I'd suspect that the cam would be different between the two barrel and 4 barrel, but have no proof. I've even seen 421 Pontiacs with a 2 barrel. Our body shop manager had a '68 Star Chief that got 20 MPG on the open road with that setup. Beasts like that had tons of torque, and even the big cars had tall axles. __________________ ~Steven '70 Chevy 3/4T Longhorn CST 402/400/3.56 Custom Camper Simi Valley, CA

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