401 casting number

hogman

Can anyone tell me the casting number for a 401 and where it would be located. I may have a replacement block and I was told it was a 401 but the displacement is not cast on the side. So I would have to check the casting number but I don't know what numbers I should look for and where they are. Are they on the back of the motor by the bellhousing?

hogman

I have found a list of casting numbers on the internet but now I need to see if anyone knows where it would be on the block. I have a factory reman block and I'm trying to figure out how to I.D. it. I was told it was a 401 but it only has a 2 barrel carb. so I may have been duped.

tufcj

Casting number is on the bellhousing flange at the rear of the block. Drivers side, toward the top. Bob tufcj

hogman

Thank you!

Lifted79CJ7

Also you can tell if it is a 401 vs 360 vs 304 because it says it under the motor mount on the side of the block. Can't get much easier than that! Also, you might want to pull the valve covers and get the casting numbers off those and see what heads you have (might have been replaced somewhere down the road). Jack

kaelen

I thought I remembered reading somewhere that the factory only made one replacement block. It could then be bored out to necessary displacement. That was why the number wasn't cast into the side. It would replace the 343 to 401.

You may have to do some measuring to find out exactly what it was built as. If you have the heads off measure the bore. 4.08 = 360, 4.165 = 401. Unless of course it was overbored. Or check the casting numbers on crank and rods.

Just found where I read that.. On the boottom of the page at.. http://www.jeepforum.com/wiki/index.php/AMC_V8

Wrench Man

kaelen wrote
I thought I remembered reading somewhere that the factory only made one replacement block. It could then be bored out to necessary displacement. That was why the number wasn't cast into the side. It would replace the 343 to 401.

One block can't replace a 343 and a 360, the 343 is a short deck and the 360 is a tall deck, all 343's '68 and '69 390 are short deck and all 360's '70 390's and all 401's are tall deck.

jeepsr4ever

The replacement or service block ahs the same casting # as the 401 3198951

ironman_gq

Im pretty sure most of the 401's came with a 2bbl carb in the jeep trucks.

kris

Nope. All 401's in jeep trucks had the 4bbl. The 2bbl 401's are from International trucks. k.

hogman

Well I found the casting number and it is a 3198951. As stated it did not have the displacement on the side of the block indicating that it is a factory replacement motor but according to the casting numbers it is a 401 so I'm happy about that. Now all I have to do is find a flywheel for this motor and a flex plate for my 290 and I can do a swap. It does have a I'm open to advice on bolting on an Edelbrock Performer Manifold, Performer Cam kit, and a Holley Truck Avenger 650+ carb., and Headers. That will be the only upgrades I do because I don't want to replace the whole drive Terrain and I don't want to have so many pony's that I break things all the time. Is this a good combo? How many horses and ft. lbs. do you think it will put out? It will not have any smog and will have headers.