I have never seen an aluminum block with aluminum caps, wether OEM, or aftermarket. What blocks are you referring too?

Cn block aluminum cap

Also, the old Ford Motorsports aluminum block had aluminum caps. At least the two I have seen did. I'm trying to think I've seen a bunch of aluminum cap blocks just can't remember.

I imagine they'd have to be quite a bit larger to come close to the strength of an iron or billet cap? Also, must have a cycle life too possibly?

mine have been in since 2005,whippled 496's,stroked 454's.there still going.

The CN block is naturally large. The caps don't seem abnormally large to fit the block. 865ci 5 kits 4 years still the same crank and main caps. Goes 5.90's in a POS backyard chassis that is way over weight. And it runs every weekend.

Seems like the L19s are a really poor choice. Corrosion is a serious concern.

If your considering eagle or scat, Here are some amazing rods especially for the money! $559!!! Tom has a wealth of knowledge. He has been in the Rod business for over 30 years and ran some of the top companies like Oliver etc. Worth looking into. They even offer a pretty sweet proprietary ARP2000 bolt with asymmetrical threads similar to the CARR.

http://www.molnartechnologies.com/

if you do some research you will find that their rods are not made in the us,same as eagle and scat,they are finished here in the states,again,same as eagle or scat.i am not saying they are good or bad as i have never used any of them.

Just to update this. Called Callies tech department and they said that they chose and still are using the ARP L-19 because it is "a better bolt", and the hydrogen impingement/corrosion issue has not been a problem in their testing. To clarify, all of the BBC Compstars feature the L-19. Food for thought.

Yes, Tom Molnar---I have heard of him---he's a local guy here. I am pretty sure he's the same engineer, and was the major part of the brain power behind Oliver's engine component designs that they produced until he left years ago and eventually started Molnar Technologies. I think he's got something like 30+ years or experience and knowledge in designing cranks and rods, etc.