hello ive got a 355 vortec stealth ram. i had tuned air fuel and had a driveable stu going for several weeks with my 2.77 gears. I recently installed 3.73 and i was intantly extremely lean... mostly 16.1 and leaner. My old tune rarely saw any leaner than 14.7. is this normal for a tune to change so dramatically? my car is a 1989 maf 6e setup. Im going to use my wideband to tune the air fuel again. back to in the area of 13.1 i have added a small amount of AE but im not really sure on how to figure out how much my stealth ram will take. My vig converter wont lock up.. how should i adjust the lockup time for the 373 gears i now have. my spark table is totally stock.. i have setup base timing and max but i need to tune the table to take advantage of the vortecs. the table ive been using for air fuel id power enrichment vs. rpm and i havent touvhed any onther tables.. what other fueling tales should i pay attention to? Lee

Are you running open or closed loop? If you are in open loop you are leaner because the 3.73 gear put the engine at a higher rpm to run the same speed you were running before.

When I tuned mine I spent more time on the rpm range that the engine runs most of the time and didn't do much at higher rpm's. This was done in the MAF tables under light load and in open loop. If this is close to the way you tuned you just need to tune higher in the tables since you are now using more air to reach the same mph. This is all for light load conditions where PE is not engaged.

I hope this helps.