[mpeastend]

Thanks to all for your answers!

Angela, wow, that's exactly what I'm looking for! Thanks so much! It's actually so detailed I can't plug in all the numbers until I find out some more values but it's what I need. You are right on about the placement of the powerband in regards to cruising rpm. GM & Dodge publish max hp & tq figures w/corresponding rpms but that doesn't tell me about the size/shape of the powerband. I will make educated guesses about them based on their stats and your calculator.

I was leaning towards the 4.10 for towing ease as I wasn't planning on doing the big wheels thing. I'm concerned about mileage on a 600 mile journey...would it be really off? I've done research on the 'net and come to two schools of thought:

1) The motor would always be spinning faster with mileage suffering but by how much is too variable to put a value on it. Most think that at a given rpm in top gear, the 4.10 would always be about 5mph slower and would have to spin approx 400-500 rpm quicker to keep up with a 3.73 & thus fuel consumption would go up.

2) Although the motor would be spinning faster, under towing situations, the motor would have to do less work/be less stressed and would therefore return better mileage. The throttle plates would be open less & less air/fuel required (less cylinder pressures) to do the work required even though the motor would be spinning faster. *Note* They were only indicating this for towing situations, since unladen it would probably just be based on engine rpms, the higher being the loser in mileage.