5.7 vs 6.1 cylinder heads?
 

What's the differences between the heads, are they interchangeable?

I know they are interchangeable i changed my 5.7 heads to 6.1 heads. i know the 6.1 heads are higher compression. they flow better as well.

Yes they will interchange. The 6.1 has bigger valves and flow more. They also have a smaller chamber so they increase compression on a 5.7. I wouldn't run the stock 6.1 heads on a stock 5.7 without an aftermarket controller to reduce timing. The HEMI Shop has a "big chamber" CNC head that is great for use on the 5.7.

Good deal, I like options ;)

The 6.1 will flow more CFM, but the 5.7 will have more air speed velocity.

Under 400 cu inch I'll take a ported 5.7 head over a 6.1 head any day.

Ported with stock valves, or bigger? I've got my eyes set on building a stroker motor at some point, and need to get my ducks in a row before I start chunking down cash :)

I used 5.7 heads with 2.08" int and 1.62" exh. on my 6.1 stroked 392. I guess you could call it reversed engineering.

any flow numbers for both?

http://www.thehemi.com/57L/flow.php
http://www.thehemi.com/61L/flow.php