TheAMCForum.com Homepage
Forum Home Forum Home > The Garage > AMC V8 Engine Repair and Modifications
  New Posts New Posts RSS Feed - What is the difference between an AMC 69 and 70 39
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Click for TheAMCForum Rules / Click for PDF version of Forum Rules
Your donations help keep this valuable resource free and growing. Thank you.

What is the difference between an AMC 69 and 70 39
 Post Reply Post Reply
Author
Message
  Topic Search Topic Search  Topic Options Topic Options
69kermit View Drop Down
AMC Apprentice
AMC Apprentice
Avatar

Joined: Oct/23/2014
Location: El Cajon, Ca.
Status: Offline
Points: 37 		Post Options Post Options   Thanks (0) Thanks(0)   Quote 69kermit Quote  Post ReplyReply Direct Link To This Post Topic: What is the difference between an AMC 69 and 70 39
    Posted: Sep/17/2018 at 11:31am
everything I have read that the bore and stroke for a 69 and a 70 390 is the same so what is the difference between piston themselves?

Edited by 69kermit - Sep/17/2018 at 11:50am
Back to Top
mmaher94087 View Drop Down
AMC Addicted
AMC Addicted
Avatar

Joined: Apr/01/2008
Location: Arizona
Status: Offline
Points: 1690 		Post Options Post Options   Thanks (0) Thanks(0)   Quote mmaher94087 Quote  Post ReplyReply Direct Link To This Post Posted: Sep/17/2018 at 11:40am
Pistons; not sure beyond the valve relief. '70 block is taller and the rods longer.
Mike
Back to Top
304-dude View Drop Down
AMC Addicted
AMC Addicted
Avatar

Joined: Sep/29/2008
Location: Central Illinoi
Status: Offline
Points: 9082 		Post Options Post Options   Thanks (0) Thanks(0)   Quote 304-dude Quote  Post ReplyReply Direct Link To This Post Posted: Sep/17/2018 at 11:42am
Different sized head bolts, a wee bit more beef in the main webbing, a taller deck height, and different crank, pistons and rods.
71 Javelin SST body
390 69 crank, 70 block & heads
NASCAR SB2 rods & pistons
78 Jeep TH400 w/ 2.76 Low
50/50 Ford-AMC Suspension
79 F150 rear & 8.8 axles
Ford Racing 3.25 gears & 9" /w Detroit locker
Back to Top
FSJunkie View Drop Down
AMC Addicted
AMC Addicted
Avatar

Joined: Jan/09/2011
Location: Flagstaff, AZ
Status: Offline
Points: 4742 		Post Options Post Options   Thanks (0) Thanks(0)   Quote FSJunkie Quote  Post ReplyReply Direct Link To This Post Posted: Sep/17/2018 at 3:06pm
Heads. The 1970 390 is a 1969 390 on Flonase. Less congestion. 
1955 Packard
1966 Marlin
1972 Wagoneer
1973 Ambassador
1977 Hornet
1982 Concord D/L
1984 Eagle Limited
Back to Top
ADAM12MATADOR View Drop Down
AMC Addicted
AMC Addicted
Avatar

Joined: Dec/03/2011
Location: New City, N.Y.
Status: Offline
Points: 518 		Post Options Post Options   Thanks (0) Thanks(0)   Quote ADAM12MATADOR Quote  Post ReplyReply Direct Link To This Post Posted: Sep/17/2018 at 3:56pm
The 68-69 rods are 5.790 long and the 70 rods are 5.858 long. I believe the diff in the pistons are the location of the pins in regards to the piston height. 
Back to Top
 Post Reply Post Reply
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.03
Copyright ©2001-2019 Web Wiz Ltd.

This page was generated in 0.125 seconds.
All content of this site Copyright © 2018 TheAMCForum unless otherwise noted, all rights reserved.
PROBLEMS LOGGING IN or REGISTERING:
If you have problems logging in or registering, then please contact a Moderator or