Can I put this barrel ext. on my 16 inch h-bar bushmaster barrel? (currently wearing a standard ext)

http://www.lewismachine.net/product.php?p=124&cid=12&session=9675b85ae8c6dcad9e1c9eceed3fab28

Is this setup an "upgrade" compared to standard rifle feed ramps?  (m4 ext, with a non m4 upper reciver?)

The rifle/ barrel has had 1700 rounds thought it, if I was able to put an m4 bbl ext in my barrel, would there be any headspace issues?

It it worth it, if the time/cost of putting the m4 ext was a non-issue?

Brownell's has the tools to do it. But it's a bigger PITA than I'm interested in doing.

Answer to this is sell old barrel and upper and buy new barrel along with new upper.

I was LUCKY once.  I'd not intentionally try this process ever again, unless there was some unavoidable situation that absolutely required me to.

If you really, really, really want extended ramps, you can Dremel them in, like some do (some better than others).  I'd get the proper receiver with factory machined and anodized
ramps and Dremel the present extension to proper spec, but that's just me.

i dont wanna highjack.. but whats the diffrence from normal to M4 feedramps?