Amc 360????

I have a 73 CJ 5 that has been significanly modified. According to the
VIN it originally had the AMC 304 V-8. I have verfied that it has a 360 (cast in the engine block), but can not find additional information. There is a tag on the right valve cover 509H06. Does this give me any additional information if I need to do some work on this engine? This vehicle sat for several years in the desert and I think most gaskets will need to be relaced.

 

5 = 1972
09 = September
H = 304 2V
06 = day of month

You still have the 304 valve covers, almost certainly from the original engine.

Shouldn't be a problem though - the 360 did not change much over its lifetime. <edit> You realize how similar the 304 and 360 are, don't you?

 

Thanks for the info. I was hoping the 304 and 360 were similar, but I really had no clue. I have been putting off doing some work on this because of my inexperience. I have the Chilton manual, but it does not have any info on the 360 just the 304. Another thing I will need to tackle is the wiring. Excuse the ingorance, but how can I tell if it has a 6-Volt charging system? Thanks in advance!!!

 

1973 would be 12 volt.

 

The 304 and 360 are externally identical except for the "304" or 360" markings. The AMC 360 is a AMC 304 with a larger bore.

Here's what's different:
pistons
flywheel
block (but only because of the larger bore; otherwise identical)
harmonic balancer
cylinder heads (the 360 has bigger valves, requiring a different cylinder head)

The 360 is a drop-in replacement for the 304, as long as you use the 360 flywheel.

Forget the Chilton's manual. Get a Jeep Factory Manual, or use the online '72 manual at www.trailforge.com

Heh. 6 volt systems were ancient history by 1973. 12V systems replaced 6V for most applications in the 50s. AFAIK VW was the last holdout for 6V, but the switched to 12V in 1967.

 

Really? The blocks are identical? I don't get it, if they are the same block you should be able to bore a 304 from 3.75 to 4.08 in right?

 

No, the bores are cast different. The cylinder wall is about the same thickness in a 304 or a 360. The two blocks are cast with different cores and different molds so that the machining to make the final bore diameter is minimized. Everything else is the same, except the cast-in displacement numbers.

BTW the last of the 360s (ca 1990) do not say 360, but instead say 5.9L.

 

So basically the blocks are different, but share all the other parts. I can see how making two molds with the same external dimensions but different bore diameters would be cheaper.