ashbros

I have a big m block with nodular caps.

How difficult would it be to get a complete set of Billet Main Caps for this block and would the bolt holes fit?

Should I go with Dart caps or look for aftermarket types?

I know I would have to line bore at a minimum, but are there any other issues I need to know about?

zipper06

I kid you not a couple yrs. ago i bought a dart little M block to build the 434" i now have going in my Malibu, it came with nodular iron caps, someone ask me why am i not going to Billet caps? I ask them if i'm going to break the nodular iron caps, what will break instead if i put billet caps on?
I still have the nodular iron caps, if they were that weak of a link, don't you think Dart would put put billet caps on from the factory, just to make sure they don't lose face?
Now i know we put billet caps on stock blocks but they come with gray iron caps not nodular.

I just know Carl Hink will have an answer for this one.

JMO

Zip.

ashbros

Hey thanks ZIP.
Thats some of the info I am looking for, Pros and Cons of Ductile vs. Billet caps

Pwmax

Unless its a 2000+hp engine, then I wouldn't bother. I know most pro-stock guys run Nodular caps. I had a Sonny's/AR 5 inch bore space Pro-Stock block in the shop last fall, aluminumn block, guess what kind of caps it had? Nodular. This was an 804 inch engine, that made somewhere in the neighborhood of 1700hp. Another thing to consider, is all diesel blocks use nodular caps. They support sometimes 25:1 compression with 40psi of turbo boost, at 2000rpm. Talk about hard on mains.

Frank

hink

To change the caps to billet will cost more then its worth as the rear caps needs a ton of machining as its pretty much just a block of steel when you get it and buy the time you machine it in line boring and line honing your better off to buy a billet cap block.

zipper06

That's what i was thinking Carl, when i made the statement, but i knew you had a lot more insight and experience than i did when it comes to the actual cost.

Zip.

mopar1962

if I were to use an aftermarket main cap it would be aluminum,absorbs vibration better than iron or billet, and make dam sure the caps fit tite in their registers, usually need machining,studs, then line bore........ QUOTE,shit fire save matches