Milodon main caps are CNC machined from ductile material with high strength, which has the proper balance of strength yet is not too rigid, allowing the transfer of increased shock loads to the crank and bearings.
In this case, when it comes to hardness, more is not better.
Only .030" of material removal is required upon initial installation, allowing 100% cleanup on a damaged or crooked block.
The kit includes the drill bushing used to drill and tap the side bolt holes.
Anyone with a hand drill and a tap can install the side bolts.
If the block has square main registers, only a standard align bore is needed to finish the job.
Milling the mains is only necessary if the main registers are not square.
The side bolts are angled to pull from the side walls of the block and not the flimsy main web area.
An angled bolt will require a massive amount of additional load to flex or stretch, let alone break.
The cap is heavily loaded against the register step by the side bolts, which stops "cap walk".
Cap walk causes a significant amount of unforeseen bearing damage and horsepower loss.
All necessary bolts, washers, and the drill bushing are included in the center three cap kit.
For maximum strength, the installation of Milodon main studs is highly recommended.
While mild steel main caps may look like main caps and are economical, they are the wrong material for a performance application.
True "deductile" iron caps take a beating and return to their original shape, saving the bearings and continuing to perform well.
Very rigid mild steel caps act differently and do not absorb the impact from the crank, usually pounding out the bearings if run hard.
It's like jumping out of a second story window.
Deductile iron caps also cut better during align bore.
They heat and expand at the same rate as the block material, keeping the crank bore round instead of going oval.
