6.1 heads on 5.7 block

[Hemi Rebel]

As my super bee sits waiting for an engine, i have a few options i can choose from. I have a 6.1 thats being built for a turbo. Its being delayed to to machine work. Nothing tragic like the block is stuck in machine shop purgatory or anything. Its a long uninteresting story.
Anyway, i can wait for that to be built, or... I have a 2006 5.7 I managed to piece together out of used stuff left over from motor swaps at work. The bottom end has new rings and bearings. I have a fresh set of heads. New 5.7 car intake. I can finish putting that together, put it in the car and get the wiring sorted out and get it running. Then swap for the 6.1 when its ready. Or.......dress the 5.7 block in orange and use the cam, heads and intake from the 6.1. It will look the part, but what is involved? I know its all bolt together stuff, but what does the compression come out to? What little i have seen is from othet forums. I even read you can double up on the stock head gasket to lower compression. Seems every thread gets muddled cause they quickly turn to "use eagle heads". Are they basically 6.1 heads? Regardless, i have all the 6.1 top end ready to go. Just curious what the compression will be or if i should just build the 5.7 as a 5.7

 

[Moparmatt72]

The 6.1 heads just have bigger ports over the 5.7, its a good upgrade for the 5.7 to swap the heads and intake and gain more power. Its straight across swap, dont believe there is a difference in compression maybe a slight increase but not much.

 

[Hemi Rebel]

Well, it would be going from an 85cc chamber to a 74.5 cc. Stock 5.7 is round 9.6:1 compression. Just curious what it would be with the smaller chamber and a .040 head gasket with a 4.100 hole. Anyone been there done that? If it's only around 1 point higher that would be sweet.

 

[Moparmatt72]

I'd guess that's about as much or two points. Haven't done it personally last new hemi I had was the 6.1 in a charger, but heads, intake even the stock exhaust manifolds all out flow the 5.7 stuff, I've heard the exhaust manifolds flow like 40% more over the 5.7 ones.