I like the 4 bolt caps... will it STOP cap walk... no
but it does stabilize the cap better... but the cap is
still bending/bouncing to give you the cap walk... thats
weight and/or detonation... I have 1 SB that has 4 bolt
mains(not cross bolted) and I like that block.. it has
shown to be good over the years.. the outer bolts are 3/8
but the caps are massive.... billet steel
EDIT
looks like you might have to grind the side washers
to clear the pan(just guessing on that.. but looks close)

They DON'T.........nothing does

I have a similar block. Don't know whose caps they are, but it uses 3/8ths bolts also. Do you know the torque sequence and spec for these caps?

Monte was surprisingly terse in his reply, but the benefit of the aluminum main cap (as he has explained before) is that it absorbs some of the shock transferred to the cap that a steel cap will pass on to the block. Think of the rebound difference when striking a metal object with a dead-blow hammer vs a normal hammer.

What we all refer to as "cap walk" is really not that at all. What we have is a lack of clamping force and that lets the cap "bounce" and is what creates the fretting on the faces.

Monte was surprisingly terse in his reply, but the benefit of the aluminum main cap (as he has explained before) is that it absorbs some of the shock transferred to the cap that a steel cap will pass on to the block. Think of the rebound difference when striking a metal object with a dead-blow hammer vs a normal hammer.

What we all refer to as "cap walk" is really not that at all. What we have is a lack of clamping force and that lets the cap "bounce" and is what creates the fretting on the faces. As myself and others have stated, you even see this on iron Mega-Blocks, that have ductile caps and are cross bolted. These blocks are actually MADE for the cross bolt cap, like the HEMI, yet does not eliminate the issue. So the thoughts of an aftermarket cap, placed in a block that was NOT designed to do that, is not going to stop it either. The better blocks survive the issue better.......because, well, they are BETTER blocks, but the problem itself is NOT gone. Girdles, cross bolts and all the other stuff, that are an attempt to "lock the cap down" simply don't work. Now do they help?........that's all a matter of speculation.

Do the aluminum caps "fix" the issue?.......absolutely not, but it is my impression and others, that alum absorbs some of the movement and puts less stress on the main webs. Again, NOT a fix, just another form of bandaid.

So how do you "fix" the cap bounce........in a factory design B block, the simple answer is you don't. Your only hope is that the block is beefy enough to take it and that design includes Mega-Blocks, HEMI blocks and so forth. So how COULD it be fixed? In my opinion, that would take a total redesign of the bottom end, with much larger and beefier main webs, bigger studs and enough material to accept a splayed angle, 4 bolt cap like other brands

That`s what THEY say but what about the expansion and contracting deal being alum. in an iron block.......

Well the good thing is we can all agree that the main caps need to be upgraded. I'm not trying to promote any system of doing that. I view this as a learning PROCESS! First off think about what cap walk is. Under a load the main cap is forced down. This caused the sides to pull in. No longer held tight by the register the cap can move around. We see the same elongation happen in a connecting rod. Rod bearings are designed to allow for this. Think of the cap register as more of a way to preload the cap. This is why blocks with loose registers have more cap movement. Mopar blocks are not the only ones that suffer from cap movement. Ask a machinist how they fix the problem in other blocks and most of them will say that they use a stronger cap and force them tighter into the register. Think about this as well. Have you ever seen aluminum caps used to increase strength on any other engine block??? (again not saying they are a bad investment) I trust the machinist that have worked before me. Someone had to be the first to use aluminum caps and I'm sure they had a good reason. I just don't think they made that reason clear. I do intend to use aluminum caps in the future. For now I'm testing the cross bolted caps. After doing the machine work to install the caps I do not feel that I have removed any material to weaken the block. The cross bolts are 5/16 and they torque to 24 ft.lb. Just enough to help support the register.

Was just stating my curiosity about the different metals expansion rates and figured it would have to influence bearing clearances somehow but maybe not......