Small block 400's???

[68Gold/white]

What years did the small block 400's come in these pickups??? I've seen one in a 79, and maybe one in a 78. These were both original engine pickups, had quadrajet carbs, AND both these pickups were 4WD...
Just wondering what the date range was of these engines in pickups...

I do know the SB 400 came in 71 and 72 big cars (maybe other years, possibly 70, not sure about 73 and newer...) they only came with 2 Barrel carbs, but still ran awesome, my Mom had a 71...

[DoubleDubya]

A friend of mine had a '76 with a 400. It was a 4x4 too.

[MikeB]

Go down about half way here:

https://en.wikipedia.org/wiki/Chevro...l-block_engine

[Matt Man]

I think the 400 was last offered in 1980. Also the k30 pickup from 77-80 had the 400 as the biggest motor option no 454 k30 until 1981.

[1976gmc20]

I worked for a dealer 1975/1976 and they were just becoming available in K models so probably the 1976 model year.

It seemed like a big deal at the time, but I drove the new ones and I couldn't really tell the difference between the 400 and the 350. Maybe I would have if I took them out on the highway or up in the mountains.

My 1980 350/SM465 seemed to have about twice the power of my 1973 350/TH350.

[MikeB]

Originally Posted by 1976gmc20

It seemed like a big deal at the time, but I drove the new ones and I couldn't really tell the difference between the 400 and the 350. Maybe I would have if I took them out on the highway or up in the mountains.

You probably would have noticed it in the mountains. The 400 made at least 50 lb/ft more TQ than a 350 of the same year. And it did it at very low RPM. I'd guess around 400 lb/ft at 2500 RPM. Great for trucks and station wagons.

[Killer Bee]

Originally Posted by MikeB

Go down about half way here:

https://en.wikipedia.org/wiki/Chevro...l-block_engine

holy smokes!

In all, over 100,000,000 small-blocks have been built in carbureted and fuel injected forms since 1955 as of November 29, 2011.

[1976gmc20]

Originally Posted by MikeB

You probably would have noticed it in the mountains. The 400 made at least 50 lb/ft more TQ than a 350 of the same year. And it did it at very low RPM. I'd guess around 400 lb/ft at 2500 RPM. Great for trucks and station wagons.

Yeah, it was only a couple miles from the downtown showroom/shop to big dirt lot where they stored most of the inventory. Sometimes they were right off the transport and not yet tuned for the altitude. The set up shop was also downtown so everything got ferried back and forth.

But there was a big steep hill right behind the storage lot, where salesmen would take customers in a 4x4 to show off how they would climb. It was almost "mandatory" for us flunkies to take a turn up and down the hill in every new 4x4 Had to make sure they weren't defective, you know

[MikeB]

Originally Posted by 1976gmc20

But there was a big steep hill right behind the storage lot, where salesmen would take customers in a 4x4 to show off how they would climb. It was almost "mandatory" for us flunkies to take a turn up and down the hill in every new 4x4 Had to make sure they weren't defective, you know

Sounds like a fun job! I always wanted to work at the local Chevy dealership when I was in high school in the mid 1960s. Was on a first name basic with the parts guys and a couple mechanics. I got a really good parts discount (several columns over from list price), and they even gave me a pair of mechanic's coveralls with a Chevy service emblem on them. I was really proud of those things and wore them whenever I was working on my cars (a 51 and then a 55). Can't imagine that happening at today's mega-dealers, but hopefully it still goes on in small towns.

[Pontiac1976]

I never seen any 400 4 bolt blocks in person. But 400 2 bolt blocks are cheaper easier to be changed to a stronger 4bolt block. A shop machine can machine the block new stronger 4 bolt caps pretty cheap then you 400 4bolt block cost be stronger too.
75-80 years you would per would be 77-80 they came with hard seats. But you can get them 75-76 reworked harden seats add. I own a 400 2 bolt aftermarket 4 bolt caps to days cap much better early to med 80's

[MikeB]

Found this on another forum written by a guy I know and respect:

DO NOT USE ANY STOCK 75-LATER CHEVY HEADS ON A 400. In 1975, Chevy started cutting corners on their heads to save a little weight. In 75 the heads had a second exhaust crossover port added which produced more head heat. And by the late 70s, all SB heads (except the Bowtie heads) were light weight, thin wall castings. ANY machinist who has lots of experience with SB heads will tell you that Mid-70s and later heads are either cracked when they come in, or, they probably will crack soon.

[1976gmc20]

Originally Posted by MikeB

Sounds like a fun job! I always wanted to work at the local Chevy dealership when I was in high school in the mid 1960s. Was on a first name basic with the parts guys and a couple mechanics. I got a really good parts discount (several columns over from list price), and they even gave me a pair of mechanic's coveralls with a Chevy service emblem on them. I was really proud of those things and wore them whenever I was working on my cars (a 51 and then a 55). Can't imagine that happening at today's mega-dealers, but hopefully it still goes on in small towns.

They offered to train me to work in the machine shop mainly turning brake drums, but probably foolishly I turned it down because I wanted to be outside doing things instead of stuck in a little room all day. After about nine or ten months working there I quit and got a service station job at a small town up in the mountains. Less than a year after that, I started working at a little sawmill that was really way up in the mountains. Later I started logging. Did I mention that I liked to work outside?

There pretty much are NO small town dealers anymore. The GM dealer in our county got shut down in 2009 (they still sell/service farm equipment). So we would have to drive about 70 miles to the regional mega dealer.

My relatives in TX are I think the only small town (about 2K pop) dealer that survived the bailout blitz, just because they were selling so many units over a large area. They had just bought two other dealerships in nearby towns in adjoining states in order to expand, but GM.gov forced them to shut those down

[MikeB]

Originally Posted by 1976gmc20

My relatives in TX are I think the only small town (about 2K pop) dealer that survived the bailout blitz, just because they were selling so many units over a large area. They had just bought two other dealerships in nearby towns in adjoining states in order to expand, but GM.gov forced them to shut those down

Yeah, driving through the small Texas towns, most of those dealerships are gone.

Funny story, but Fiat/Chrysler closed down a successful Dodge dealer in a small Texas town, thinking the customers would drive 50 miles to the nearest dealer in a larger town. But what happened was a Ford (or Chevy???) dealer in the small town took most of that business away from Dodge over the next few years. Turns out it wasn't just the town buying trucks, it was the surrounding area of farms, ranches, oil & gas facilities, etc. No doubt Fiat/Chrysler underestimated loyalty to local businesses.

[dajn]

I have never owned a small block 400 but I remember as a kid my dads 71k10 had a small block 400 in it. I have no idea what year the engine was. But I always remember that pickup and all the things my dad did with it. Always overloaded, abused and worked hard. And it always seem to get the job done. It the attached pic, my dad is moving a little shed a couple miles down gravel roads for a friend of his that got the shed for next to nothing. Me and my two brothers are riding in the box. Early nineties.

[1976gmc20]

Originally Posted by MikeB

Yeah, driving through the small Texas towns, most of those dealerships are gone.

Funny story, but Fiat/Chrysler closed down a successful Dodge dealer in a small Texas town, thinking the customers would drive 50 miles to the nearest dealer in a larger town. But what happened was a Ford (or Chevy???) dealer in the small town took most of that business away from Dodge over the next few years. Turns out it wasn't just the town buying trucks, it was the surrounding area of farms, ranches, oil & gas facilities, etc. No doubt Fiat/Chrysler underestimated loyalty to local businesses.

My "other family" sells vehicles in at least five different states, or at least they did. I've sort of lost track of things since my dad passed away. I guess they really weren't so happy about the lost son from a previous marriage But I wish them well, anyway.

[b454rat]

400s went from 1970 to 1980. I had one that was a 4 bolt, 1973 I believe. 4 bolts were only made from 70 to 73/74, can't remember. But as mentioned, a 2 bolt made into a 4 bolt is stronger than a factory 4 bolt. I never heard that about later heads, I had a **** ton of heads from late 70s and into the 80s, never had cracks. Only had one run warm, but that was a 400 bored .040 over, highway was fine, but around town would warm up. Radiator was new, shroud, pulled a lot of air, but block couldn't transfer or radiate or whatever want to call it. Still ran good tho. I have a 400 block all ready to be put together. Just need the funds....

[Pontiac1976]

DO NOT USE ANY STOCK 75-LATER CHEVY HEADS ON A 400. In 1975, Chevy started cutting corners on their heads to save a little weight. In 75 the heads had a second exhaust crossover port added which produced more head heat. And by the late 70s, all SB heads (except the Bowtie heads) were light weight, thin wall castings. ANY machinist who has lots of experience with SB heads will tell you that Mid-70s and later heads are either cracked when they come in, or, they probably will crack soon.

I did know about the heads. But I was not using factor heads anyway but would that be due to the over heating as 400's did make more heat top end of the motor if you did not keep eye on it, or your cooling was not 110 %

[68Gold/white]

Originally Posted by b454rat

400s went from 1970 to 1980. I had one that was a 4 bolt, 1973 I believe. 4 bolts were only made from 70 to 73/74, can't remember. But as mentioned, a 2 bolt made into a 4 bolt is stronger than a factory 4 bolt. I never heard that about later heads, I had a **** ton of heads from late 70s and into the 80s, never had cracks. Only had one run warm, but that was a 400 bored .040 over, highway was fine, but around town would warm up. Radiator was new, shroud, pulled a lot of air, but block couldn't transfer or radiate or whatever want to call it. Still ran good tho. I have a 400 block all ready to be put together. Just need the funds....

BUT, the small blocks were NOT offered in 70, 71, or 72 pickups, correct???

I've looked in aftermarket parts books, none list the SB 400 as an engine...

You can tell the later heads form the earlier heads by the edge below the spark plugs. If the edge is straight with one little notch to clear the dip stick tube, THAT is an early head. The later heads are scalloped all along that edge, likely a mandate to save weight...

THe 882 heads, which WERE an earlier casting were crack prone. I would avoid them if possible, even though they are big valve heads...

[THI]

Correct on the 400 SBC not being offered in the 1970-1972 trucks, the 400 listed when looking for parts is a 402 BBC. I am not sure of the exact year they started showing up in square bodies, I thought is was 1973 but looking around I can only find them showing up in the 1975 year model and later.

Any of the 400's I have pulled out of the trucks, my experience is with 1977 and 1978 trucks that had original 400's, they had a small valve (1.72 intake, 1.5 exhaust) heavy casting head. The ones I have pulled out of mid 1970 cars had 882's - the first generation of the light weight heads. 624's were even lighter and more crack prone than 882's but I have only found those on 350's.

[68Gold/white]

The 383 stroker engines started showing up, years ago, I'm guessing around 1990. Folks were grinding down the larger 400 stock cranks and putting them on 350 blocks. Called them stroker 350's (383). Many were afraid of the 400 block. You had to drill the steam holes in heads, if the heads were not originally on a 400. It's NOT that difficult!!!

My engine builder back then, built a lot of 400's. I know of 5 of them. They ran incredibly well!!! The cylinder bores of the 400's are siamesed. The cylinder have no coolant between them. I've heard of engine builders shying away from them because of this. Some say the cylinders don't stay round after heads are bolted up and engine is at operating temp....I'm not knowledgeable of these things. I do know my engine builder used a torque plate when honing his. None of his were problematic, at all.

The small block 400 is the only small block I'd ever want to build, for any reason!!! I know the LS engines are awesome in many ways, but I'll take a 400 every time!!!

I started this thread asking about 400's in 70-72 pickups. A fellow car enthusiast insists SB 400's were in these pickups (I knew they were NOT) I dropped the conversation, not wanting to wound a friendship...I asked here to make absolutely for sure...

[MikeB]

Originally Posted by 68Gold/white

I started this thread asking about 400's in 70-72 pickups. A fellow car enthusiast insists SB 400's were in these pickups (I knew they were NOT) I dropped the conversation, not wanting to wound a friendship...I asked here to make absolutely for sure...

Well, there were pickups with "400" emblems in 71-72, but the engine was a 402 big block! But from what I can find, the small block 400 wasn't used in pickups until 1975.

Very good info from you above on how the 383 craze got started and what a great engine the 400 can be when built correctly. But I would want to use 5.7" or 6.0" rods instead of the stock 5.565".

[1976gmc20]

Originally Posted by 1976gmc20

I worked for a dealer 1975/1976 and they were just becoming available in K models so probably the 1976 model year.

It seemed like a big deal at the time, but I drove the new ones and I couldn't really tell the difference between the 400 and the 350. Maybe I would have if I took them out on the highway or up in the mountains.

My 1980 350/SM465 seemed to have about twice the power of my 1973 350/TH350.

Duh, I just got to thinking about it, and actually I worked for the Chevy dealer 1974/1975, so the current model year then would have been 1975 not 1976.

At the time I thought about buying a brand new K20 with a 350 and 4 speed with the employee discount. But I would have had to sell my 2 year old pickup myself. It was an idea because my pickup was worth about as much used as the new one with the discount. I just couldn't figure out how to float the thing since I didn't have anything else to drive.