400 sbc
Race Director
Joined: Mar 2003
Posts: 11,608
Likes: 780
From: Eustis ( Area 51 Bat Cave ) Fl
Late 70s maybe 80 my dad bought his dream car an avanti it had a chevy 400 sb,
My dad liked crazy builds, he was a retired navy plane tech and machinist so had the skills,
He wanted one of the 572 caddy engines but he didnt want to cut things required to fit it,
So he was one to believe a lot of the 400 sb myths but looked into it and built the 400 like one would have built a 350 back then dispelling the myths,
It was insane, it felt like a bb but wound up faster than my 454s did,
People that have one hang on to them they love them, if i did a small block that would be it...
My dad liked crazy builds, he was a retired navy plane tech and machinist so had the skills,
He wanted one of the 572 caddy engines but he didnt want to cut things required to fit it,
So he was one to believe a lot of the 400 sb myths but looked into it and built the 400 like one would have built a 350 back then dispelling the myths,
It was insane, it felt like a bb but wound up faster than my 454s did,
People that have one hang on to them they love them, if i did a small block that would be it...
Drifting
Joined: Aug 2005
Posts: 1,443
Likes: 65
From: Wauconda IL
400 SBCs were made from 1970 to 1980.
1977-1980 was in trucks only.
Good used/original blocks are getting harder to find and folks are asking a fortune for worn out junk.
But, if I stumbled across a decent short block for a good price, I wouldn't hesitate to use it.
Just my .02
1977-1980 was in trucks only.
Good used/original blocks are getting harder to find and folks are asking a fortune for worn out junk.
But, if I stumbled across a decent short block for a good price, I wouldn't hesitate to use it.
Just my .02
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
You said it, most wanting a lot for an old 400 that may or may not be good
If you even found a good magnafluxed 400, guys want 4-500 for them, add 1000+- machining, plus the rest its an expensive "chance".
If you even found a good magnafluxed 400, guys want 4-500 for them, add 1000+- machining, plus the rest its an expensive "chance".
Burning Brakes
Joined: Nov 2011
Posts: 1,170
Likes: 201
From: Willoughby Ohio
When you add machining costs and sonic testing you usually end up close
to the cost of the Dart shp block which is better in many ways. As stated earlier a much more reliable engine for not much more expense.
to the cost of the Dart shp block which is better in many ways. As stated earlier a much more reliable engine for not much more expense.
Drifting
Joined: Aug 2004
Posts: 1,883
Likes: 124
From: Lubbock TX
^ sonic testing is the only thing that a production block needs that a Dart doesn't. They still need to be bored and honed, decked, etc. unless you order it from Dart that way...in which case, you'll still pay for the work. I've built a lot of engines for less than the cost difference between an aftermarket block and using a production piece.
It all depends on how you plan on driving it. If it's a daily driver with an occasional romp to 6 grand, a production block will be fine. If you're going to drive it like you stole it from Harbor Freight, you'd be better off with aftermarket.
The break between '76 and '77 seems to be where GM lightened them up a bit. I have a couple of '75 castings stuck back in the dark recesses of my shop, can't seem to make myself let them go...
It all depends on how you plan on driving it. If it's a daily driver with an occasional romp to 6 grand, a production block will be fine. If you're going to drive it like you stole it from Harbor Freight, you'd be better off with aftermarket.
The break between '76 and '77 seems to be where GM lightened them up a bit. I have a couple of '75 castings stuck back in the dark recesses of my shop, can't seem to make myself let them go...
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
283's , 307, small journal 327's, 400's, and a bunch of 396 and 402 BBC's.
Nobody wanted that stuff.
Racer
Joined: Jun 2013
Posts: 484
Likes: 43
From: NJ
I was the opposite. When I cleaned out my shop, I told all my friends come and get what ever blocks you want. Because they are all going to the iron scrap yard. I hauled away blocks through whole motors
283's , 307, small journal 327's, 400's, and a bunch of 396 and 402 BBC's.
Nobody wanted that stuff.
283's , 307, small journal 327's, 400's, and a bunch of 396 and 402 BBC's.
Nobody wanted that stuff.
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
the 396 bbc's even the highest hp vette models used to be very cheap because everyone wanted 427 and then the 454. It was the same time with the later 402 bbc
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Race Director
Joined: Mar 2017
Posts: 11,949
Likes: 4,507
From: Virginia
Not trying to be glib, I looked into a bunch of these threads when trying to decide what to do in the future to my car (no urgency, I need to make the car stop in a straight line first).
A cheap Dart 400 iron block is about the same as cheap Chevy Performance aluminum LS3 block, $1700-. Assuming that the cost of building them from there is about the same (correct me if I'm wrong, I'd expect the LS to cost more, but still be in the noise), why would anyone build a 400 when you can benefit from an additional 30+ years of engine development, and save a bunch of weight, too? You can even add a single or dual-plane carb intake, and have the stock carb back on top.
Am I missing something?
A cheap Dart 400 iron block is about the same as cheap Chevy Performance aluminum LS3 block, $1700-. Assuming that the cost of building them from there is about the same (correct me if I'm wrong, I'd expect the LS to cost more, but still be in the noise), why would anyone build a 400 when you can benefit from an additional 30+ years of engine development, and save a bunch of weight, too? You can even add a single or dual-plane carb intake, and have the stock carb back on top.
Am I missing something?
Racer
Joined: Jun 2013
Posts: 484
Likes: 43
From: NJ
Sometimes its just about old school builds.
For me, I went with a small block because the majority of my friends are big block junkies and there are also a few LS guys. The small block is always the underdog. I like to be the underdog
For me, I went with a small block because the majority of my friends are big block junkies and there are also a few LS guys. The small block is always the underdog. I like to be the underdog
Drifting
Joined: Aug 2005
Posts: 1,443
Likes: 65
From: Wauconda IL
No question that the LS is a superior design.
The choice for me boiled down to the effort involved in trying to fit an LS motor in a chassis never designed for one.
Some folks love the challenge of fabricating a bunch of stuff to make it work but for me, I wanted something that is truly a bolt in affair.
Having to re-engineer exhausts, mounts, cooling, pulley and belt routing etc. was more effort than I wanted to invest just to go fast.
The 400 SBC gave me exactly what I wanted without having to re-engineer the entire car around it.
Just my .02, your mileage will vary..
The choice for me boiled down to the effort involved in trying to fit an LS motor in a chassis never designed for one.
Some folks love the challenge of fabricating a bunch of stuff to make it work but for me, I wanted something that is truly a bolt in affair.
Having to re-engineer exhausts, mounts, cooling, pulley and belt routing etc. was more effort than I wanted to invest just to go fast.
The 400 SBC gave me exactly what I wanted without having to re-engineer the entire car around it.
Just my .02, your mileage will vary..
Race Director
Joined: Apr 2000
Posts: 17,676
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
........
Heel & Toe
Joined: Feb 2018
Posts: 23
Likes: 1
Plus you have to look at cylinder placement, lifter bore placement, cam tunnel placement, Dart blocks seem to be spot on compared to the old production blocks.
Navigator
Joined: Jul 2016
Posts: 9
Likes: 0
I currently am attempting to install a 400 sb in my 87 c4. the 400 has flat top +20 over pistons. My ?s is w heads & cam should I use and shold I stay flat tappet or do a roller conversion?
Safety Car
Joined: Sep 2001
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From: Glenbeulah Wi
Le Mans Master
Joined: Nov 2016
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From: Lake Tahoe, CA
