This may or may not have been discussed before, idk I cant really find the answer I'm looking for so MAYBE not. I have a bone Stock 1991 3.1 RS with 148k miles. Haven't had the car for long but Im not looking to keep the V6 that's in it, I just don't like the fact that it can't even get out of it's own way... With that said I have read post after post of people taking a 350, putting vortec heads, Holly 650 or larger Double Pump carb, mild cam, and RPM air gap intake sitting in front of a 700R4 and successfully seeing 23 to 25 mpg out of it. I'm curious to know if anyone has taken a BONE STOCK vortec 5.7, and swapping the intake to except a carb and seen the same results or better?