Have 3:23's now and looking to get a little steeper. SLP has 3:42's on sale now but everything I read says won't notice a difference. Will 3:73's adversly affect my gas mileage with the price over $3.00 now. I drive about 800 to 1,000 miles a month. Also how to you correct the speedo on a 94? I had 3:73's in 69 SS but it was rarely driven and it made it come alive, but top speed was only 115 with a close ratio 4 speed.