who here has or is running with no exhaust sleeve with a matching port?

I'm asking this because was on Google and read somewhere that rice does this with no ill effects, saw a few post that he says this.

any one with real world experience?

 

I have run with no exhaust sleeves in a na 4 port 13b in a 77 repu had no ill effects other than running a little hotter than i wanted, did big rad and e fan problems cured. ran it for three years before i sold it...ran awesome with a header and rb intake/ dellarto set up

 

have done it quite a few times with lots of Km's on many engines
with nil ill effects as long as you match the exhaust to the new opening
, no alum erosion,, turbo still spools ,, radiator still works