|
|
Item Posts
Sort Order
|
|
|
Anyone know: AMC 304 Heads?
|
|
Posted: 03/15/10
09:50 AM
|
|
Anyone know: Over the years did AMC ever make physical changes to the heads on the 304?
I recently finished replacing the heads on my 304 (verified by the "304" stamp on the bottom of the block). The new heads, were decked, have new valves, and were cleaned by a professional race shop in Phoenix, they came from a 1980 304 (also verified). They work like a champ!!! My CJ has never run better, and I've had it for 23 years. It's scary fast now, I should have changed the heads a long time ago.
The old heads are nothing like their replacements, the rocker setup is totally different, the fire ring was bigger & the area shaped differently, the exhaust bolts were all 3/8, and the performer intake did not sit properly between them.
I have yet to have anyone recognize these old heads. Does anyone know how to identify the casting markings? I've been told the rocker set-up resembles an older Chevy engine.
I would like to post photos if you can tell me the website.
.
Dirty Deeds DunderJeep 77 CJ5 304
|
|
|
|
|
Posted: 03/15/10
01:18 PM
|
|
The 1970 to early-71 heads with 51cc chambers (casting number 319-6291), and the mid-70 to mid-73 58cc heads (casting numbers 321-2993 and 321-3948). Both heads have the superior dogleg exhaust port and studded rocker arm mounts. The only real difference between them is a thicker layer of metal inside the combustion chambers. When you compare the two side by side it is very noticeable, especially between the valves.
Using the gas your hybrid saves!!
|
|
|
|
|
Posted: 03/15/10
01:19 PM
|
|
http://www.planethoustonamx.com/main/prepping_amc_v.htm is where i found the info on the heads
Using the gas your hybrid saves!!
|
|
|
|
|
|
|
Posted: 03/15/10
04:05 PM
|
|
Outstanding, thank you very much!!!
.
Dirty Deeds DunderJeep 77 CJ5 304
|
|
|
|
|
Posted: 03/15/10
04:31 PM
|
|
This is a great site, the production figures & decoding information is very helpful.
thx again
.
Dirty Deeds DunderJeep 77 CJ5 304
|
|
|
|
|
Posted: 03/15/10
07:05 PM
|
|
no problem! glad you could use it
Using the gas your hybrid saves!!
|
|
|
|
|
Posted: 03/17/10
08:17 AM
|
|
The number is 321 2990-4, they appear to be 58cc version used from mid 70 thru mid 73 and are for sale.
.
Dirty Deeds DunderJeep 77 CJ5 304
|
|
|
|
|
|
|