Gear ratio question

[BBC78K20]

Hey guys I'm new to the forum and figured I'd ask a question that I can't quite get an answer to. I plan on pulling an enclosed car trailer weighing around 7-8k. I have 37" tires and currently have 4.10s. Its a project for now just wondering if I should go 4.56 or 4.88. Opinions?

[Irish_Alley]

ive done some towing with my 79 k20 350/sm465 with 4.10s and 38s. i didnt have a problem. now i didnt pull real heavy loads occasional car trailer and other trailers. one good thing if i needed it i could use 1st gear to get going. and depending on where youre hauling (mountains or planes) would effect the ratio choice also. now in my 91 crew cab with a cummins and 4l80e with 4.10s ive hauled a heavy dump trailer full of trash. the total weight was 12840 lbs. my best estimate of the truck is 7500. i only had 33s, with 37s she would of been a dog even with the cummins. i would at least go with the 4.56. though it might hurt your mpgs but your rpms will only rise a couple hundred more than what they are now at cruising speeds but the less effort when taking off might counter that

[BBC78K20]

Ill be pulling through some hills for sure. I bought 4.88's for the front a while back but wasn't sure. With overdrive it might not make much of a difference between the two, not sure. But thanks for the reply!

[Irish_Alley]

between the 4.88s and the 4.56 youre only talking about 100 rpms difference. if you already got the front i would get the rear put in and try it out without doing the front that way you can at least sell or return the front