401 swap

are 401's that hard to come by?

 

Getting harder to find them.

The block alone is worth quite a bit.

High5

 

Well that's good to know.

 

there is talk about an aftermarket company coming out with an aluminum amc block. :drool: i would think that they would make 401s for sure and probably 360 and 304 bores also. amc's always get the rap of parts are hard to find, but people say the same about flatfenders and those early curved fenders too. the parts are out there.

 

They do bring up a good point.

The 401 is not seem much any more and would proably have more value down the road.

350 conversion is almost so standard that really it is no big deal.

My buddy owned a jeep for three year that had a 401 in it . It was rusted out and falling apart. He did not give a crap about it. He never changed the oil or anything.

He bought it for $500 and when he sold it he got $2,000. I think someone wanted that motor.

Good luck on your build. Please post some pics when you are done.

JUST REMEMBER

JEEP stands for:

Just
Emptied
Every
Pocket

R) R)

 

Well based on yalls responses, I like the thought of having a 401. Now I just need to get to work (at my real job) so I can JEEP again.

 

Take a look on some of the auction sites. The 401 blocks are bringing in really big bucks. Almost up there with the 390. The AMX/Javilin crowd goes for them. I will assume, without trying to be rude that the 401 is worth more than your two jeeps together. Everyone keeps finding this cools stuff except for me.

 

Oh no that's not rude at all. That's music to my ears.

 

Technically the 401 is a really interesting engine too. A 401's displacement is about as large as you can go with that block - the bore size is at the limit for the cylinder spacing, and the cylinder walls are fairly thin compared to other engines. A 401 can be overbored 0.030" safely, but only some if any blocks can be overbored to the next standard size of 0.060". The blocks are made of a special alloy that is high in nickel (as I undertand it) which strengthens them and allows the relatively thin cylinder walls. Of course, this raises the OEM cost over a regular cast iron block.

I also understand that they don't wear very quickly, so 401 blocks should not be routinely overbored. Blocks that have been overbored once to 20 or 30 should likely be sleeved rather than overbored again. This can make the rebuild of a 401 significantly more expensive, and raises the value of a low-mileage, factory bore 401 block significantly.

The crank and rods of a 401 are forged steel (strong!), unlike the cast crank and rods of the 304 and 360. The bearing size and spacing is different between the cranks, so you cannot use a 401 crank in a 360 block or vice-versa.

The 401 is a true high-performance engine, and because of it's steel components and superior block alloy, can withstand lots of abuse. This also means that the stock 401 should last a lot longer than a 304 or 360 in normal use.

Unfortunately, the 401 uses the same aluminum timing cover as the 304 and 360, so it will suffer the same loss of hot idle oil pressure at high mileage. Lots has been written on the net about the the AMC V8 oiling problems - do a search and you'll find lots of links. And be sure to check the hot idle oil pressure on your engine with a quality aftermarket mechanical oil pressure gauge.

 

I swear I'm getting all giddy. I bought the motor because it was freshly rebuilt and it was a good price for any motor in good running shape. Not to mention he threw in the rest of the jeep. I knew nothing about these motors. I can't wait to get it all together. I think this weekend. I'm gonna really hit it hard, as I don't have to work tomorrow. Hopefully by 6 or 7 in the morning the wrenches will be flying.

 

This is a crazy idea but if the motor is worth as much as some people are saying why not sell it and rebuild your motor and have some money left over for other stuff.

 

That's a logical idea, but I don't claim to be too logical. I think that after I build the best cj I can from what I have, I'll have some stuff left I might can get rid of. That'll give me a little room to breath. I don't need much because I only have about $1100 tied up in both jeeps.

 

I remember Tim saying something in a post that I can't find about the front and rear needing to be geared the same? and I need a little clarification on this before I go to swapping axles. Looking to knock a huge dent in it this weekend. I'm ready to drive around the yard.

 

um, yes, the front and rear need to be geared the same, or at least with in .01 i.e. Some axles might have 4.09 and others 4.10.

If they don't you're gonna rip the something up, T-case, driveshft or Axle gears.

 

Ok maybe for the time being I should swap both axles from the 77 to the 74. I'm sure this is easier than moving the drivetrain. I do want to inspect all three good differentials. How do I id the gear ratio?

 

www.bulltear.com has all the oil mods you need. they also have nickel plated timing covers, that like the amc block, resist wear because of the nickel. other oil parts are there also, like a billet oil filter adapter (highly recomended).

pull the covers and read the number on the ring and devide. or count the teeth on the ring gear and devide by the number of teeth on the pinion.

 

Fixing to go get at it.