Value of a 400/402 big block?

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Raider L

Full Access Member
Joined
Sep 1, 2020
Posts
1,892
Reaction score
1,001
Location
Shreveport, LA
First Name
William
Truck Year
1974
Truck Model
C10
Engine Size
355
I concur on all points in spades!!!!

I have a bunch of car mags, i.e. Car Craft, Rod & Custom, Hot Rod, Super Chevy, Chevy High Performance, and many others from the middle to late '90's that have all kinds of articles on building up 402's. From what I've read it's what GM called a 396 for insurance reasons. The reasoning behind that was if they said it was a 396, it wouldn't be as much to insure it as a 427 or a 454 which the insurance companies took a very dim view of. For some reason they thought a 396 wasn't as dangerous as a 454 in a Vette or a Chevelle, or worse a Nova. They could just see some 16 year old kid wrapped around a telephone pole, but if the car had a 396 in it he wouldn't be wrapped around it as far.
 

Craig Nedrow

NADAR UNDER THE RADAR
Supporting Member
Joined
Sep 1, 2018
Posts
1,036
Reaction score
2,184
Location
Washington State
First Name
Craig
Truck Year
1973 (have two), 1985
Truck Model
K10, K20, C20
Engine Size
350, 454, 6.2 Detroit
I was there when they came out.....we all drooled. Been in some very fast 396's. 402 was a .030 over 396. 4.125 stroke shaft makes it a 454, but different from "the" 454, 4.25 bore, 4" stroke.
 

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
5,451
Reaction score
8,695
Location
kansas
First Name
Rick
Truck Year
1975
Truck Model
c20
Engine Size
350
Here's a tid bit for you a 396/402 although not huge but here's something to consider your getting longer rods and better heads than any factory sbc. Good heads and long rods make power.
 

idahovette

Full Access Member
Joined
Aug 7, 2016
Posts
7,270
Reaction score
15,874
Location
Weiser Idaho
First Name
Perry
Truck Year
1975-1979
Truck Model
K20-K10
Engine Size
350
I concur on all points in spades!!!!

I have a bunch of car mags, i.e. Car Craft, Rod & Custom, Hot Rod, Super Chevy, Chevy High Performance, and many others from the middle to late '90's that have all kinds of articles on building up 402's. From what I've read it's what GM called a 396 for insurance reasons. The reasoning behind that was if they said it was a 396, it wouldn't be as much to insure it as a 427 or a 454 which the insurance companies took a very dim view of. For some reason they thought a 396 wasn't as dangerous as a 454 in a Vette or a Chevelle, or worse a Nova. " They could just see some 16 year old kid wrapped around a telephone pole, but if the car had a 396 in it he wouldn't be wrapped around it as far."
This statement would depend on the level of the 396 build and The kid driving it!!!!!
 

85K304SPD

Full Access Member
Joined
Mar 29, 2022
Posts
472
Reaction score
702
Location
Las Cruces, NM
First Name
Richard
Truck Year
1985
Truck Model
K30
Engine Size
402
Ricko nailed it. Its like a 383 or 400 SBC with all the better features. Bigger valves, rods, etc... heavy duty and still stock dependable. Sure it is a little bit heavier, but these trucks are already heavy.
 

GTX63

Full Access Member
Joined
Nov 27, 2022
Posts
933
Reaction score
3,791
Location
Tennessee
First Name
Ty
Truck Year
1985
Truck Model
K10
Engine Size
350
One of the fastest street cars I ever rode in was a 69 Chevelle with a 396/402. This was in the mid 80s. It pulled the front wheels at will and was a legit daily driver. Times were different.
I'd have no problem snagging one for a squarebody and they are as easy to work on as any Gen 1 small block.
 

Strick

Full Access Member
Joined
Nov 25, 2020
Posts
1,354
Reaction score
3,315
Location
Dunn, NC
First Name
Harold
Truck Year
1979
Truck Model
C20 Crew
Engine Size
350
It's a Big Block Chevy...is there any question? So, if it were a tall deck 366 or 427 I may hesitate to build it for a Square; but a 396 will nestle nicely in the engine compartment. I may be a bit biased as I have 4 396/402 engines and a couple 454's.

HS
 

Turbo4whl

Supporting Member
Supporting Member
Joined
Oct 30, 2019
Posts
3,126
Reaction score
7,257
Location
Downingtown, PA
First Name
Wayne
Truck Year
1974
Truck Model
Jimmy
Engine Size
350
I concur on all points in spades!!!!

I have a bunch of car mags, i.e. Car Craft, Rod & Custom, Hot Rod, Super Chevy, Chevy High Performance, and many others from the middle to late '90's that have all kinds of articles on building up 402's. From what I've read it's what GM called a 396 for insurance reasons. The reasoning behind that was if they said it was a 396, it wouldn't be as much to insure it as a 427 or a 454 which the insurance companies took a very dim view of. For some reason they thought a 396 wasn't as dangerous as a 454 in a Vette or a Chevelle, or worse a Nova. They could just see some 16 year old kid wrapped around a telephone pole, but if the car had a 396 in it he wouldn't be wrapped around it as far.
So that helps me understand. GM called the 402 a 396 in 1970. In 1971 they labeled it as a 400. That caused confusion with the 400 SB. The last year they finally called it the 402. As far as I know only 3 years as a regular production in the full size sedans.
 

85K304SPD

Full Access Member
Joined
Mar 29, 2022
Posts
472
Reaction score
702
Location
Las Cruces, NM
First Name
Richard
Truck Year
1985
Truck Model
K30
Engine Size
402
Ok, so I just pulled out a 383 and dropped in a 402 in my 85. It is an original big block truck, so it needed a big block back in it. It looks correct now, but not a "big ole'" 454 gas hog. I haven't pulled any loads or anything with it yet, but so far it seems to run well. I feel better about it now.
 

85K304SPD

Full Access Member
Joined
Mar 29, 2022
Posts
472
Reaction score
702
Location
Las Cruces, NM
First Name
Richard
Truck Year
1985
Truck Model
K30
Engine Size
402
Ok, so I just pulled out a 383 and dropped in a 402 in my 85. It is an original big block truck, so it needed a big block back in it. It looks correct now, but not a "big ole'" 454 gas hog. I haven't pulled any loads or anything with it yet, but so far it seems to run well. I feel better about it now.
You must be registered for see images attach
You must be registered for see images attach
 

ChuckN

Full Access Member
Joined
Nov 8, 2022
Posts
1,318
Reaction score
4,005
Location
Bellinham, WA
First Name
Chad
Truck Year
1981
Truck Model
C10
Engine Size
350
TBH, I’ve been quietly keeping my eyes open for something like that. Mainly, because as much top-end work I’ve done on engines over the years, I’ve never gotten into the bottom end, because I’ve never had to. The marketplace and Craigslist are full of well worn big blocks for relatively cheap, and when the time comes I’d like to pick up something just like this to learn on. Checking tolerances, cleaning it up and running it just so I could have the satisfaction of doing it. Not saying that’s why you would do it @Grit dog but I do feel like there’s a lot of value in these things.
 

GTX63

Full Access Member
Joined
Nov 27, 2022
Posts
933
Reaction score
3,791
Location
Tennessee
First Name
Ty
Truck Year
1985
Truck Model
K10
Engine Size
350
So that helps me understand. GM called the 402 a 396 in 1970. In 1971 they labeled it as a 400. That caused confusion with the 400 SB. The last year they finally called it the 402. As far as I know only 3 years as a regular production in the full size sedans.
I bought a 1965 Caprice with one of the first 396 engines. Factory holley carb and solid lifters that came in the 425 hp motor but this one was supposedly, and listed, as the 325 hp engine.
You could purchase a Chevy full size sedan with the 396/402 from 1965 thru 1972.
 

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
5,451
Reaction score
8,695
Location
kansas
First Name
Rick
Truck Year
1975
Truck Model
c20
Engine Size
350
On 1970 they bored the blocks .030 making all 396s 402s for the 1970 model year they just didn't bother rebadging the cars. Trucks still got the 396 for 1 more year. Here's a fun question the 366 and the 396 have the same stroke do you think the blocks were cast with enough meat to accept a 396 bore. The 283,302,307,327 small blocks had this same situation. I cannot remember how to tell the difference but the 283-327 blocks had 2 different castings 1 was the same casting just bored smaller so you could bore it to 4 inch the other casting it was hit or miss
 
Last edited:

Old Guy Bill

Full Access Member
Joined
Sep 10, 2023
Posts
429
Reaction score
1,323
Location
KY
First Name
Bill
Truck Year
1978
Truck Model
K20
Engine Size
400
Several years ago I built a sweet ‘69 Camaro.
Bought a 396 with a ‘68 date code & suffix from a passenger car.
Bored 30 over, hydraulic Comp cam, 750 double pumper Holley with a Muncie 4 speed and 12 bolt rear end. That big block would annialate the tires.
I loved that car and it turned heads.
You must be registered for see images attach
You must be registered for see images attach
 

Forum statistics

Threads
44,168
Posts
950,764
Members
36,283
Latest member
Cantrell299
Top