Big block in a 1978 Impala - Impala Tech
Engine General Engine Discussion.

 
LinkBack Thread Tools
post #1 of 4 (permalink) Old 03-05-2012, 05:47 PM Thread Starter
jjp
 
 
Join Date: May 2009
Location: MI
Posts: 2
 
Big block in a 1978 Impala

Came across a clean "Granny" 1978 Impala......small block now (of course) w/air.....how difficult to install a big block and th350....I know the 200 in there now will interchange with a TH350...but not sure about the big block....any help would be great!....I know you guys will be thinking WHAT?...Thanks again
jjp is offline  
Sponsored Links
Advertisement
 
post #2 of 4 (permalink) Old 03-05-2012, 08:29 PM
Moderator
 
Join Date: Jan 2006
Posts: 12,457
 
Welcome to the Team Jim!

I have one in my 1985 and it is the same car as your 1978. I used Hooker Competition Plus headers for a Chevelle but I chose the 4L80e transmission as a big block will break a TH350 or 700R4 transmission. If you want a three speed go for the TH400 instead of the TH350. I also had to make my own cross member for dual exhaust. To cool the added cubes I used a Griffin 1-1/4 inch twin tube radiator (Howe also makes a big radiator for the car as well).









I had to use a Chevelle oil pan from Moroso and even then I had to massage the front cross-member a bit with a sledge for clearance at the front of the oil pan (seven quart Moroso with kick outs 8-3/4 inch deep). Only other problem was the intake manifold and a Dominator carb left only an inch above a flat hood with a Victor intake manifold so I had to go to a medium rise dual plane to run an air cleaner to hide the carb and keep the flat hood I was looking for (my car looks like an old taxi cab and sounds like a small block with a hole in the muffler as I like to keep a low profile).



The beige car is the 582 big block powered car the brown one has a 406 small block under the hood that makes 513 horsepower.

Big Dave
Big Dave is offline  
post #3 of 4 (permalink) Old 03-05-2012, 08:57 PM
Senior Member
 
Join Date: Apr 2010
Location: Monroe NC
Posts: 1,094
 
Love the oil pressure switch in the valve cover.....thats one way to monitor you pressure! .
68imp is offline  
 
post #4 of 4 (permalink) Old 03-05-2012, 09:34 PM Thread Starter
jjp
 
 
Join Date: May 2009
Location: MI
Posts: 2
 
Wow...Thanks for the help....any special motor mounts, and relocation of the trans cross member for the TH 400? Will probably remove all the a/c stuff for more room....any other changes or problems to expect? Thanks a lot!
jjp is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Impala Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
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:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



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

 
For the best viewing experience please update your browser to Google Chrome