Why doesn't Ma Mopar make the 426 HEMI water block anymore?

[drobertson]

For a while now, I've been wanting to build a 426 hemi. I have read from several sources that in the late 90's and early 00's, mopar made reproduction hemi water blocks. (non-siamese bore).

I have noticed that when I look for blocks online, everybody only has siamese bore engine blocks. Why did mopar stop making the 426 water block? If I can't find one, can a siamese bore hemi block be driven on the street without cooling issues?

 

[TetanusShot]

The crate motors use the siamese blocks. The sides of the block next to the cylinders are bulged out a little for extra water. I'm sure their are a few guys on this forum who run them on the street. I'm just finishing up a 528 for street use. The only disadvantage to using the siamese mega block is the incredible weight! These suckers are well over 300 lbs from all the extra beefed up areas in the block.

 

[drobertson]

The crate motors use the siamese blocks. The sides of the block next to the cylinders are bulged out a little for extra water. I'm sure their are a few guys on this forum who run them on the street. I'm just finishing up a 528 for street use. The only disadvantage to using the siamese mega block is the incredible weight! These suckers are well over 300 lbs from all the extra beefed up areas in the block.

Thank You!!! Now I know that these will be okay for a street driven car! Now I've just got to save my pennies...

 

[moper]

They also suffered from terrible core shift. In many cases the brand new blocks were unsafe at standard bore. Others couldn't go anywhere near the claimed oversize. Basically - like most MP cast offerings - the execution sucked. So be aware of what's out there.