Milodon Main Caps

MAIN CAPS

These aftermarket main caps will strengthen not only factory 2 bolt blocks, but also 4 bolts. Unlike the factory main caps, these not only have more cross sectional strength, but the real strength secret is in the angled side bolts! 

The side bolts are angled so they pull from the side walls of the block and not the flimsy main web area. A bolt that is angled will require a massive amount of additional load to flex or stretch, let alone break, compared to a conventional straight up bolt. The side bolts heavily load the main cap against the register step which stops "cap walk". It is main cap walk that causes a great amount of unforeseen bearing damage and horsepower loss. 

Milodon main caps are precision machined from high strength ductile material which has the proper balance of strength yet is not too rigid like a billet main cap to allow transfer of increased shock loads to the crank and bearings. In this case, more is not better when it comes to hardness. 

Only .030" of material removal is required upon initial installation, which will allow 100% cleanup on a damaged block. The drill bushing used to drill and tap the side bolt holes is included in the kit. The side bolts can be installed by anyone with a hand drill and a tap. If the block has square main registers, the block needs only a standard align bore to finish the job. Milling the mains is only necessary if the main cap registers are not square. 

All necessary bolts, washers and the drill bushing are included in the center three main cap kit. For maximum strength the installation of Milodon main studs are highly recommended.
SMALL BLOCK CHEVY MAIN CAP # MAIN STUDS  without windage tray MAIN STUDS  with           windage tray
283-327 Journal (Angled Side Bolts) 11050  81128    81129   
283-327 Journal, Front Cap, 2 Bolt 11053 

350 Journal, Factory 2 Bolt (Angled Side Bolts)1 11150 81128  81129 
350 Journal, Front Cap, 2 Bolt 11153 
350 Journal, Factory 4 Bolt (Angled Side Bolts)2 11160  81128  81129 
350 Journal, Factory 4 Bolt (Straight Side Bolts) 11165  81130  81131 

400 Journal, 2 or 4 Bolt Blocks (Angled Side Bolts) 11180  81128  81129 
400 Journal, Front Cap, 2 Bolt 11183 
400 Journal (Straight Side Bolts) 11185  81130  81131 
BIG BLOCK CHEVY MAIN CAP # MAIN STUDS MAIN STUDS
396-454, 2 or 4 Bolt Blocks (Angled Side Bolts) 11200  81133  81134 
396-454 (Straight Side Bolts) 11205  81140  81141 
396-454, Front Cap3 , (Angled Side Bolts) 11210  Note 6 Note 6
396-454, Front Cap3, (Straight Side Bolts) 11211  Note 6 Note 6
 NOTE: 1-Narrow register 4.490" wide. 2-Wide register 6.200" wide. 3-Requires slight pan clearancing in some areas.
FORD MAIN CAP # MAIN STUDS MAIN STUDS
302 Two Bolt Caps (Straight Bolts) 11400  81155  81156 
351W (Angled Side Bolts)4 11420  81175  81164 
351C (Angled Side Bolts) 11440  81169  81170 
351C, Front Cap (Angled Side Bolt) 11445  Note 6 Note 6
429/460 (Angled Side Bolts) 11450  81188  81189 
CHRYSLER MAIN CAP # MAIN STUDS MAIN STUDS
318-340 (Angled Side Bolts) 11300  81183  81184
360 (Angled Side Bolts) 11310  81183  81184
354 (Angled Side Bolts) 11320  81183 
392 (Angled Side Bolts) 11350  81183 
383-440 Wedge (Straight Bolts) 2 Bolt 11360  81183 
383-440 Wedge (Straight Bolts) 2 Bolt - 5 Cap Set 11365  81188 
PONTIAC, OLDS MAIN CAP # MAIN STUDS MAIN STUDS
Pontiac 455 (Straight Side Bolts) 11500  81222  81224 
Pontiac 350-400 (Straight Side Bolts) 11505  81222  81224 
Olds 400, 425, 455 (Straight Bolts) 2 Bolt 11550  81175 
Olds, Front Cap, 2 Bolt 11555 
AUSTRALIAN HOLDEN MAIN CAP # MAIN STUDS MAIN STUDS
253-308 (Angled Side Bolts)

11570 

81145 

81146 

 
NOTE: 4-Requires SVO block pan notch or some clearancing in the #4 main web area of the pan.