Girdle? Steel or aluminum caps vs stock?

TexasRoadRunner68

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Trying to decide how far I want to build the bottom end of my 400 stroker. I should be buying a 512 kit here pretty soon. My goal is somewhere in the 600 hp/ 600 ft lbs range.

How strong are 400 iron main caps? Should I just throw in studs and align hone it and call it good? Or go to extra and put on a 440 source/Hughes girdle?

Aluminum or billet steel main caps are another $200, but I’d have to look around to find a shop that is set up to line bore, as the one doing my block only align hones.

Is the girdle and aluminum caps overkill? I’d like this motor to survive long term if I’m dumping a bunch of money in it.
 

Badvert65

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My experience with this would be to recommend the stud girdle. It is cheap insurance. When you approach the 600 HP range in big blocks, you will start to get cap walk. This will eventually crack any cap, cast, steel, or aluminum. I use stud girdles in even milder (500 hp and less) engines.
jus sayin....
 

ruffcut

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I vote for stud girdle. I have one on my race motor with stock caps/studs.
Block has low fill ceramic also.
ruffcut
 

Curiousyellow71

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Minimal we would do studs with factory caps. I wouldnt consider aftermarket caps unless your talking more power.
If its getting raced more then street driven the girdle should help its longevity and is a good idea. The 400 blocks are different year to year as far as the casting design/ strength. 440 source has great info in there block section.
 
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33 IMP

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I really like the BCR cap and girdle system. It might be overkill for your needs. I would do main studs at the very least, and a thin girdle is better than nothing (in my opinion).
I would do a sonic check of the cylinders before anything else.
 

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