If I accidently programmed 3.73 gears when I have 3.42s will I notice a difference in quarter mile times or will my spedo just be off?

 

I don't think you'll notice anything other than your speedo reading too slow. I think the transmission shifts at WOT based on rpm's, not truly a predetermined speed, so it's not like the car will work differently.

 

thats what I thought. I figured it out when I looked at the spedo and it was reading about 95 and got my slip and it said 108.

 

yep just the speedo will be off, hehe.