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73-87 Chevy _ GMC Trucks => 73-87 Chevy & GMC Trucks => Topic started by: Buddy on April 06, 2011, 04:44:51 pm

Title: ok need help with gear and axl swap quick
Post by: Buddy on April 06, 2011, 04:44:51 pm

I am looking at buying a set of gears front and back from a guy about 2hrs away from me. My truck is an 85 but I have been told my axls are from a 77. My truck has 35's and 307 gears 10 bolt in the front and 12 bolt in the rear. I have a guy who has a front and rear 10 bolt with 373's. I have been told that he 373 will make a world of differance with the power of my truck. I never go off road and I am only running a 305 with a 700r tranny. My question is , is it worth it to swap these out. i was just going to buy new gears for my 12 bolt but i think that is a little beyond me. I could easy do a axl swap I would think! does everything line up? is it just a matter of undoing the u bolts and shocks and drive shafts and thats it?  need answers asap as have to let this guy know asap. thanks guys

Title: Re: ok need help with gear and axl swap quick
Post by: Da67goatman on April 06, 2011, 04:52:11 pm

The axles will swap in fine, as long as the u-joints are the same but you have to be careful that the axles your putting in are in decent shape, gear wear, brakes, wheel bearings ect or you'll end up rebuilding them anyway.  You will see a noticeable improvement in the get up of your truck with the ratio change, and quite possibly an increase in fuel mileage due to the engine not working as hard to turn the tires.  As long as you don't plan on hammering your truck, the 10 bolt rear should hold up fine.  Also check the steering linkage for wear and front hubs, ball joints ect.

Title: Re: ok need help with gear and axl swap quick
Post by: DustyRusty on April 06, 2011, 08:55:11 pm

^^^
Ditto.

I had 33s on my truck for a time and the 3.73 handled them fine.  3.73 will be okay with 35s on that 10 bolt but I would go no bigger.  If you ever decide to go bigger in the future I would start shopping for a D60 front and 14 bolt FF rear now and forego considering the 3.73s.

Just my $.02

Rusty

Title: Re: ok need help with gear and axl swap quick
Post by: VileZambonie on April 06, 2011, 09:00:18 pm

You will need a conversion U joint for the rear shaft joint.

Make sure you remove the inspection covers and verify the ratio's

Title: Re: ok need help with gear and axl swap quick
Post by: Grim 82 on April 06, 2011, 09:07:01 pm

If I remember correctly the part number for that joint is 348.

I would jump all over that deal, but definitely make sure that they are a matched pair, and there isn't costly damage to any of it, as mentioned.

Title: Re: ok need help with gear and axl swap quick
Post by: DustyRusty on April 11, 2011, 08:42:14 pm

How 'bout an update, Buddy.  Were you able to get the 3.73s?? 

Rusty