4.56 gears GM Truck 130.. shipped

[HotRodV6]

Ok, ive been thinking about putting some more gear in the back of my truck, right now i have 3.42 and no posi, and with the 235/75 16 tires i have now that are 29.6 tall, im running just over 2000 RPM at 75 MPH.

If i got with these 4.56, and want to put on some 20's with 305/50 tires that are 32" tall, at the same 75 im running 2500.

How bad do you think the additional 500 RPM is going to kill my MPG?

My original thought was to go with some 4.10 gears.

I also have a set of 243 heads, and LS6 type cam with 218/218 .550/.550 on a 117 LSA that im going to install here soon, along with a TT3000 converter, and LT's and ORY, a CAI and Nelson tune. I want the performance for both the street and towing, but i dont want to take a huge hit on the MPG either.

What do you think, is 4.56 to much for a daily driver?

[ChevyLee]

higher the gear the more rpms it takes which means the more gas you use.