For 243's you can have them milled and use thinner head gaskets to cut the compression loss. Or if your adventurous....you can swap to flat top pistons.

I have two trucks with 5.7 engines, one has 308rwhp and the other has 243 heads and it has 349 rwhp. Both have same cams.

 

I'm saying 320-330ish and 400rwhp is gonna take some $$ but you sure can get close to it but U need to get Justins heads get them worked a nnbs manifold t-body might put u @ 380 or so

 

I'll look into that when I get another DD and can do stuff to my truck. That's a big difference with just heads.

@62 I'll be looking into that aswell and thanks for the advise.

 

do you have any track times for the setup?

 

Haven't been able to take it to the track and get some #'s.

 

thats a big exhaust duration on a low lsa for cathedral heads and a truck intake. if you mill the heads, make sure to check PTV.