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View Full Version : Where is the head csting number? and 401 pistons Q


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Lifted79CJ7
11-02-2003, 04:46 PM
I dropped a 401 from a J truck into my CJ and I am wondering what heads I have on it, along with any specs. The tag says 111702, which I tracked down to mean that it was built on Nov. 2, 1977. My question is where to find the casting number. I looked around on it, and am hoping that it is not located on the back of the head near the fire wall. The engine appeared to be stock when I yanked it and dropped it in my CJ.

The second part of my question is I am going to be doing a complete rebuild on this engine ( I have already installed the Edlebrock Performer package (timing chain, cam, lifters, intake, 650 carb) and I want to bump the stock 8.35:1 compression ration to around 9.5. Any idea what pistons to order based on the very vague info I gave above?

Thanks,
Jack

pyagid
11-02-2003, 04:55 PM
for heads look here http://www.bulltear.com/forum/viewtopic.php?t=541

if i remember the casting number is on the head under the valve covers.

not sure about the rest of your questions but there are plenty of people on this board that will know

fuzz401
11-02-2003, 05:44 PM
the casting numbers are under the valve cover between the rocker from 74 up there is not much diff all 360 401 heads are the same if you could find a set of 291 heads it would move your 8.8 to 9 or 9.5 ratio but they are hard to find
flat top will get you around 12.5:1 with a 58 -60 cc head dont know off hand for 9.5:1 might look at trw or go coustom pistons like ross or veniola

heyjavelin
12-12-2003, 10:45 PM
In 1971 AMC built about 1/2 the model year with a small dish piston that netted 9.5 to 1 compression ratio in the 401. This was called the high compression 401. Since the production rate was so low, most after market companies didn't copy this piston but there are still a few around. I have a couple sets of brand new old stock 9.5s in the back of the garage. These are still in the original 1970 box.

Heyjavelin@Yahoo.com

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