difference between chevy 350 and 400 - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 01-22-2006, 08:23 PM
Registered User
 
Join Date: Jan 2006
Location: winnipeg
Posts: 2
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
difference between chevy 350 and 400

i have a 1976 malibu with a 350 2 bolt main and a TH350 auto,. i had just heard of a 400 motor for cheap,. i have not been able to see it to know if it is a BB400 or not or the year yet,. but was wondering what differences i may encounter with switching the motors or if it would be easier bolting up a 2 bolt main motor as opposed to a 4 bolt main and keeping the TH350 tranny for the time being. thanks!
alex

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 01-22-2006, 08:36 PM
Member
 
Last photo:
Join Date: Nov 2004
Location: Indiana
Age: 60
Posts: 393
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
They are the same motor as far as installing them goes. The only real difference is the bore and stroke is different on the 400. The 2 bolt or 4 bolt main is refering to the number of bolts holding the main caps for the crank inside the motor. If your doing a motor swap its a simple change. If its a BB it would be a 396 or 402 in that area of size. It will require more changes. A big block change would require most likely heavier front springs, different motor mounts, different exhaust,bigger radiator, different brackets for alt,ps. And I probably left out a few.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 01-22-2006, 08:36 PM
Blazin72's Avatar
You got a leaky spark tube...
 
Last wiki edit: Rearend removal
Last journal entry: General Lee
Last photo:
Join Date: Jul 2005
Location: Union, WA
Age: 32
Posts: 2,868
Wiki Edits: 19

Thanks: 0
Thanked 2 Times in 2 Posts
The 400 Chevy will drop in place of the 350 without any problems. It's difficult to tell what size a small block is just by looking at it because the Gen Is are pretty much the same on the outside. Some 400s had three freeze plugs on each side of the block while other 400s had two just like the other small blocks. If you get a chance, look at the casting number on the drivers side of the bellhousing flange at the back of the block. Look that number up and it'll tell you what you have.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 01-22-2006, 08:48 PM
MI2600's Avatar
Member# 3287
 

Last journal entry: Vortec Heads
Last photo:
Join Date: Jul 2002
Location: N. Muskegon, MI
Posts: 2,632
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
The difference is about 50 cubic inches.

You can tell a 350 from a 400 by the balancer. The 350 has a consistent outer edge. The 400 has a scalloped edge.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 01-22-2006, 09:09 PM
Registered User
 
Join Date: Jan 2006
Location: winnipeg
Posts: 2
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
making sure the motor would bolt up was my biggest concern, and i really doubt this motor would be a 396 or a 402 so it sounds like this will work out good. i'll check the numbers just to make sure,.. thanks guys !
Alex
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 01-23-2006, 11:01 PM
Member
 
Last photo:
Join Date: May 2003
Location: Shreveport LA
Age: 64
Posts: 5,103
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
If it's a small-block 400, the flywheel's different (400 wheel has a counterweight).
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 01-24-2006, 12:08 AM
Chopt 48's Avatar
Registered User
 
Last photo:
Join Date: Oct 2005
Location: Toppenish, washington
Posts: 452
Wiki Edits: 0

Thanks: 0
Thanked 3 Times in 3 Posts
As M126000 and Jimfulco said, If they are both small blocks the 350 is internally balanced and the 400 is externally balanced. The 400 will have a counterweight section in the vibration dampener and a counter weight on the front side of the flywheel. The other major difference is that the 400 small blocks have Siamese cylinders (the cylinder walls are connected in the water jacket. There are two steam holes between each pair of cylinders in both the block and heads on 400's.
As long as you get those two parts with the 400 it is a bolt in swap. The trans should hold up to all but extreme abuse.
The 400 BIG block that you are alluding to is a different animal. And will take all big block brackets. I think you are referring to the 396 / 402 engines.

The visual differences between small and big block Chevy engines are very easy to recognize and you should have no trouble telling if it is a big or small block. The big block exhaust ports are evenly spaced while small block engines have the two middle ports close together. Also the big block rocker covers are quite a bit larger than small block covers.
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
the history of chevy v8's savman1 Hotrodders' Lounge 43 03-02-2012 06:57 PM
Distributor Tuning and Theory - Part 1 Rick WI Engine 35 04-26-2011 12:38 AM
El Camino Engine - 350 Chevy or 455 Pontiac bjam2 Engine 16 08-07-2007 03:45 PM
chevy 350 or pontiac 400 or 455??? MIKE T Engine 17 02-04-2007 07:34 AM
Chevy 400 Small Block to 350? jdt40u Engine 4 07-20-2005 11:19 AM


All times are GMT -6. The time now is 11:01 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.