I've been punting some ideas around and could use some input, especially from anyone who has sleeved a 401.
I think the 401 rocks, and I think that it builds torque so well for it's size due to the crank design... but I'm no expert.
I'd read about sleeving the 401 to ~4.374/500ci and running bb ch*vy rods/pistons and a moldex crank. Seems to me it ought to just pound out the torque unlike a Caddy 500 because of what I think is a better designed crank.
I was pretty excited to see the ICH AMC 500 being built and that motivated me even more to research this a lil further for a lower cost option since the iron 401 block is tough enough on it's own virtues (and mega cheaper).
What my concern is largely is that if the bore was sleeved to meet the 4.374 in an iron block would that effect the cooling for a road running rig? I know drag racers fill the water jacket and I don't have that option.
Whatcha think and what would the Moldex crank cost (would ICH's crank work in my iron block?)?????
I know its not that expensive to build a 427 AMC stroker and to sleeve an overbored 401...hmmmm I have a .060 over 401 sitting here from Hammer (froadin.com) that I am thinking of punching...I should do a buildup on the SOB and see where its dynoed.....but I have alot on my plate right now
Dyno is where I was going, really curious to see if this AMC would out crank a big block running the same cubes and minimal other mods, polished heads, port matched stock iron exhaust (non-smog), balanced and cammed for peak torque around 2,400-3,000rpm, performer manifold and the big Truck Avenger carb.
I don't know how or what the differences are with the Moldex crank other then stroke, but the stock 401 crank had an advantage in the larger weights and rod journals (for torque) unless I'm mistaken. I think the crank design had a lot to due with how responsive the 401 torque growth is with subtle mods.
Do you think I may have something here?
Could it be sleeved to 4.374 and still run cool enough?
I've never seen one sleeved so I don't know if this is even going to sacrifice any water jacket volume.
I am not sure what we did end up with when we over bored the shinto' out of a 401 but the only advantage other than reground stroke is they will nitride the crank for a small fee.....
In their online catalog it looks like Indy Cylinder Head would probably put together a balanced crank kit (with a specified comp ration, I'd run 9.5:1)... leaving me to just get the sleeves. Do you have a price list for ICH? I tried to call and they are closed so I can't even order a catolog.
Moldex crank @4.150 Stroke
Eagle H beam Rods (6.200x2.100)
Forged pistons (Wiesco?) w/.927 free floating pins @ 9.5:1 comp
(for the 500CI AMC)
Suitable rings for a street/offroad 4x4
Set of sleeves w/4.374" bore for my 401 core
Crank/rod bearings
Reciprocating parts balanced
Harmonic balancer if other then stock 401 is required
OK Elliott and MC, you guys have my complete and undivided attention on this one!! This sounds too fun! You guys need to see if building this monster is possible. Keep up the great work!
Jack
Lifted79CJ7, Thanks
Apparently it's been done for drag racing, where they sleeved a block, used a moldex crank, and ran C*vy BB pistons and rods.
For my purposes (low rpm) I think the Wiseco forged pistons and Eagle rods are probably way overkill for running 9.5:1. At that comp ratio I could probably use a rod that was a lot cheaper and even cast Ch*vy pistons... flat tops?
Don't know if ICH sells those Moldex 401 cranks outright or requires a core, that is sure to make a difference in price.
Currently I'm spending all my money building a shop to even work on my projects so it would be awhile before I could venture into this, and I was going to start into my doubler..... However, planning is critical and I want to pool more information so I can get a guy to do some desktop dyno work to map out the cam grind. Plan to start with hyd cam to build the motor and dyno for comparison to what you get for 500CI in the Caddy (and to test the cam grind), then... funds/interest permitting swap in roller cam/lifter/rocker setup and re-dyno.
I have a NP435 and Dana 60/C14ff drive train to run all the torque through so that end of things is pretty well set to go.
I really have no idea about the sleeving capacity of this block for overboring, so I don't know if the water jacket capacity would even be effected.... possibly not.
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This sounds too fun! You guys need to see if building this monster is possible. Keep up the great work! 
