I use a cheap AEM wideband to tune my Holley 770 and 870 on my '79 Ranchero, it has been VERY reliable, have had it 7 years with no issues. It has helped me achieve extra power and MPG out of my 472 BBF/C6 combo, with no OD, I got 15.2 mpg(doing 70-75mph) on a long interstate trip from central...