Would it be simpler and cheaper to swap out the front and rear ends with the I 5 Hummer? Rather than change gear sets? Also I have been told the 08 Alphas came with either the 8.0 or 8.6 . I ran the VIN but didn't find any info on whai I have currently

 

Yes it would be cheaper depending on local cost of used parts and whoever told you any H3 came with anything but an 8.6 rear does not know what they are talking about. The only difference I know of is 2009+ 8.6" use a larger pinion bearing. The difficulty part is that the 2008 alpha came with a cast iron front housing and 4.10 gears. The only non alpha that came with cast iron diff and 4.56 gears was 2009+ 5 cylinder adventure with front locker so it might make more sense to regear front and swap the rear end with one from a salvage yard.

 

Good to know local salvage yard has 2. Will check for iron front housing thanks

 

Bruce, why the regear? All H3s Came with an 8.6" as atvspeed said.
I did it due to 37" tires, I just want to know why you want to do it?

 

if its a daily driver and you are still running semi stock aka 30 to 33" tires your fuel mileage will be considerably worse at highway speeds butif its jusy a wheeler it wont matter. now if u up to 37+ a regear would be absolutely essential imho. you cna do a gear to rpm calc on spicer website. 4.56 gears with 33" tires at 65mph you are looking at 3k rpm.

 

here is a better one as u can input your final drive. if memory serves cprrect our final drive is .7
Engine RPM Calculator

 

would like to go to 33's or the new 34.5 and pull my camper. The truck cam wit 34.5 on 20 in rims and up here in the mtn's we need a little help so I am thinking 33's and 456's plus there is 2 setting in the bone yard where I can trade my rear diff in for just the extraction fee

 

word of advice. nothing wrong with the 35s. but for mountainous areas i highly recommend goodyear duratracs. they are amazing on off and on wet icy and snowy pavements. they are available in 35 and 33s. great tires. i got 92k out of a set on my 06 hummer when i lived in washington. frequent trips into the mountains in snow rock and ice hauling campers etc. best tires ive ever owned and the only i will buy. well worth the money. also in the passes where chains are required on alot of vehicles you wont need them. theyre just flat out great tires. they have thw m+s mountain cert which surpasses most of the m+s certifications. thwyre a hyvrid at tire meant for anything you can throw at them including mud just make sure you buy load rated E for the thicker sidewall. ride is smooth and quiet also

 

yep got the dura tracks on my 79 Bronco but wont be getting into that serous of off roading with the H3 being its the wifes daily driver. Just setting it up to camp and play. Its the first GM vehicle I have bought since I quit buying Suburban's [ and their rotten trannys ] in 85 and have found it to be everything the Wrangler is for a lot less. Mine had just over 80k on it when I bought it.

 

make sure to put on an external tranny cooler. i love haydens. on amazon theyre cheap and so ridiculous easy to install into factory lines with 3/8 hose barbs. tranny will last forever for a small fee of 40 bucks