360 Heads

[1968Dart]

I have a set of 360 heads, casting number 4027596, I know they are '77 or newer, but I am wondering how well these heads will work on a 318, over the stock heads. I am wanting to know what CC these heads are and what kind of compression ratios these garnered on the engines they came off of. The only reason I am going with these heads is because of the hardened valve seats. I have a set of 50cc 273 closed chamber heads, but I need to put in hardened valve seats. Any info on the 360 heads is greatly appreciated. Thanks in advance.

[rumblefish360]

Well, they'll put your 8-8.5 comp ratio in the basement. The heads, if not closed chambered design, will have up to 72 or so cc's. Compared to the 318 head, it's a cavern. It will breath better, but not worth it until your tryin to run real fast.
You can mill them .060 to raise the comp to a better level. I believe it produces a 9-1 ratio on a 318.
For a street ride, your better of porting out the 273/318 heads. Install the hardened valve seats in them as well. The smaller port widow gives a higher velocity charge to the clyinder. This will produce better torque and HP for a mild machine.

[jimbo7074]

If this is just a good running street 318,I would try to find as set of casting#302 heads.These were the heart shaped swirl port 318 heads.They have a better exh port and I believe are around 60cc's.They are ready have hardened seats,so just give them a small porting job,and they should be ready to rock.

[rumblefish360]

Good point jimbo7074

[Karl43]

I put a set of 77 360 heads on a 318 that had 10.5:1 pistons. The increased compression height of the piston brought the compression down to 9.2:1 with the larger 72 cc heads. Car runs great and I can even run 89 octane. I drive it everyday. Mine were 72 cc's. Pretty much count on all 340/360 stock heads to be 72 cc's.

[Tony W]

Putting 360 heads on a 318 will usually go from 8.5:1 down to 7.8:1. I have a page devoted to 318 builds. Check it out:
http://www.geocities.com/alwest_83/318.html

[Karl43]

You can also have the 340/360 heads milled up to .060" before you have to mill the intake also. This will give you the larger ports and bigger valves without sacrificing compression.

[1968Dart]

I have bought a set of the "302" casting heads instead. I am wondering what I should do to them before I put them on.

[jimbo7074]

Myself I would go to larger 1.88 intakes and 1.60 exhaust valves,but that depends on your budget.If you stay with the stock valves,I would definitely have them mildly ported,and cc them to figure out your compression.I do feel that these heads are a better way to go on a 318,and you have made a good choice.