5.8 or 5.4?

[Crazyredsvt]

Hey I have a 5.8 at it’s limits FBO 10% lower 2.4 upper cams E85. Making over 800rwhp to the tire. I want more power so I ordered a Gen3R and my question is do I build the 5.8 or go with a 5.4 iron block? I’m looking to make a solid 1200rwhp+

 

[Catmonkey]

I think the 5.4 may have slight edge in the strength department, but assuming either block is sleeved, I don't think it's going to make a whole lot of difference.

 

[2011 gtcs]

If you're going to put a Gen3R on and you're already at 800+whp just build the engine. It's not worth damaging your 5.8 block.

As for you building the engine, keep your 5.8 and have L&M add darton sleeves. The 5.8 block will hold all power you can through at it once you build the bottom end.

 

[Klaus]

I would go with the 5.8 block. The AL blocks are stronger than the FE blocks regardless of the old wive tales on this. You will have to sleeve it either way. Just built mine and made 1000 whp with conservative CR and boost.

 

[biminiLX]

100% with Klaus.
Build the 5.8 or a ‘11-12 sleeved 5.4
You want the aluminum block and need 11:1 for this.
My tuner has a built 5.8 non sleeved 10:1 shortblock ready to go around $10k and I have a Gen 3 that made 1050rwhp.
PM if interested
-J