View Full Version : AMX390 Lower Compression?

10-05-2009, 07:20 AM
OK I have been reading all these posts for some time now. Lots of great information here, but havenít found what I am looking for. I have a 1969 AMX 390 that has been in our family since 73 and itís mine now. The car is untouched other than tires and brakes and I am going through it as a driver restoration. I am not interested in racing it, just weekend cursing and a little fun at the stop lights some time, the way I remember it as a kid.

The engine needs to be overhauled, still runs smooth but a fair amount of blue smoke, its time. I think to ensure it will run well on pump gas, will need to drop the compression a bit is what I get from this forum. I would like to keep the stock heads, will likely need new pistons any way. What would you all recommend for pistons, cam and the like.

Any suggestions would be appreciated.

Big Bad AMX
10-05-2009, 11:59 AM
If you haven't already read it you might find this thread helpful. (http://www.amx-perience.com/AmericanMotorsForum/showthread.php?t=98&page=1&pp=10)
I think it covers most of what you're looking for.


10-06-2009, 10:39 AM
Thanks, I had read through this earlier, but have gone back over it in detail again. My first thought was to just go to a dished piston to lower the compression. But all I am really doing there is giving up performance with out trying to recover it in any other ways. I think the new heads with larger chambers will accomplish both here. I have been to AMX Enterpriseís web site, I have not called them yet but thought I read some where in this forum he was retiring? Also I see in American Performances Site they are closing up shop this month till further notice, the economy is getting us all.

I will need to start searching to see what I can find I the way of heads to rebuild out there. I am looking for a 70 or newer 360 Ė 401 dog leg head, then manifolds to go with it.

10-08-2009, 06:13 AM
I have been searching this section, i thought i read the casting number for the dog leg heads here but can't find it. I have located some heads from what is advertised to be a 74 360 - 401 engine. Does any of this look to be the correct numbers?

Ident: 3216090 cast.,
Ident: 3220503 cast.,
Ident: 8123303
Ident: 8124621
Ident: 8128640

Thank you for the help.