Lakec423 Posted December 28, 2015 Report Share Posted December 28, 2015 I have the axels with the leaf springs I know I'm gonna have to move the saddle for the leafs and figure out breaking but should I run a 4x4 Chevy steering box also what should I do about drive shafts ? It's a passenger side drop so that's in my favor the axels are Chevy 10 bolt with 3,73s. Quote Link to comment
Stoffregen Motorsports Posted December 28, 2015 Report Share Posted December 28, 2015 If you're planning on running full width Chevy axles I would consider using a Toyota steering box mounted on the outside of the frame. You can control the bumpsteer better with a longer drag link. I wouldn't spend any money on those 10 bolt axles though. 1 Quote Link to comment
Lakec423 Posted December 28, 2015 Author Report Share Posted December 28, 2015 I got an extra fronts and parts there pretty common in Florida how do I post pics ? Quote Link to comment
datzenmike Posted December 28, 2015 Report Share Posted December 28, 2015 It's a 4x4 you need more gear not less. A 3.73 will barely turn the tires. Is this from an S10 chev because aren't the entire wheels going to be outside the fenders??? Go with early 80s Toyota. Lots of support for them and the fit. Tons of gear options and LSD. Quote Link to comment
Lakec423 Posted December 29, 2015 Author Report Share Posted December 29, 2015 Yeahh tires are gonna be out there that's not a prob and in 4 low it should pull fine running down the road in not gonna take it much over 55 Ill let you guys know how it turn out I just don't know what I'm gonna do about drive shafts I was gonna go with a Chevy steering box but I'll just have to learn as I go Quote Link to comment
Lakec423 Posted December 29, 2015 Author Report Share Posted December 29, 2015 I'll break more with a smaller axel I feel like k would have less breaks with these it's a 4 cylinder not a 350 lol Quote Link to comment
Lakec423 Posted December 29, 2015 Author Report Share Posted December 29, 2015 Also once this motor goes it's getting a 4.3 with a 4 speed granny low and the transfer case will hold up cause I had a buddy that put one in a s10 on 38s boggers and never gave him any trouble exept breaking mounts Quote Link to comment
Lockleaf Posted December 29, 2015 Report Share Posted December 29, 2015 Not sure what your question about drive shafts is. They have to be customized no matter what, so what is the real question? Diameter, material, etc? Passenger side drop on a 720 doesn't really matter. The tcase drops dead center, so it can go to either side with equal efficacy. 3.73 is a highway gear for trucks. It's going to take lots of rpms to get them turning well, so when shifting on the trail, you will have to stay in high rpm. You say you won't go above 55, but those gears are meant for highway speeds. Stock you are likely running 4.11, maybe 3.9, so you're already reducing low end useability from stock. That's why Mike recommended against them. This won't help you create a trail truck. It's the recipe for a wide 100 mph cruising truck. For steering, I recommend you do a lot of reading of other 720 SAS builds and see how they resolved issues. Poormans720 is a good place to start. Google 720 sas or his screen name and read up. 1 Quote Link to comment
datzenmike Posted December 29, 2015 Report Share Posted December 29, 2015 Yeahh tires are gonna be out there that's not a prob and in 4 low it should pull fine running down the road in not gonna take it much over 55 Ill let you guys know how it turn out I just don't know what I'm gonna do about drive shafts I was gonna go with a Chevy steering box but I'll just have to learn as I go Is there such a thing as a chevy 4x4 without power steering???? If there is you'll wish you had it with big tires. Helps if you have a PS pump on your '81. The 4.3 should have it. Are there laws in Florida regarding exposed tires without fender or flair coverings?? Most places won't allow it on the road. The '81 4x4 ran 4.375 gears. The stock tire size is about 27". Going to 33s will seem like 3.57 (worse than the 3.73) and be sluggish as hell on acceleration. Your lowest crawl speed will also go up by 22%. To maintain the same crawl speed on 33" tires you would need a 5.30 differential swap Quote Link to comment
Lakec423 Posted December 29, 2015 Author Report Share Posted December 29, 2015 The motor in it know is blown and the motor im putting a motor out of an 85 Nissan in it has power steering so there goes that issue and it's going on 35s Quote Link to comment
Lakec423 Posted December 29, 2015 Author Report Share Posted December 29, 2015 And would it matter that k have a 4 speed ? I have a 5 speed tranny also laying around Quote Link to comment
datzenmike Posted December 29, 2015 Report Share Posted December 29, 2015 A 4 speed will go as fast as a 5 seed. No problems there. Quote Link to comment
Lakec423 Posted December 29, 2015 Author Report Share Posted December 29, 2015 My 4 speed topped out at 70 I doubt that Quote Link to comment
Lakec423 Posted December 29, 2015 Author Report Share Posted December 29, 2015 I figured the 5 speed would be better and my speedo was off might of been about 80 but still Quote Link to comment
datzenmike Posted December 29, 2015 Report Share Posted December 29, 2015 If you top out at 70 in 4th that would be around 3,800 RPM I would guess. This is where the air resistance equals the power made by the engine to push through it. A five speed is an over drive gear that lowers the PRMs of the engine to save gas at cruising speed. Lower RPMs will make less power at 70 and you will go slower. Here's a sobering thought about air resistance. It takes 4 times the power at 40 MPH to go 80 MPH. Doubling the speed takes 4 times the power. 2 Quote Link to comment
Stoffregen Motorsports Posted December 29, 2015 Report Share Posted December 29, 2015 I'm guessing you are trying to throw together a truck with full width axles on the cheap, and you think you can do it for labor only. Have you ever built an offroad truck before? Are you good at fab? What kind of welder do you have? Do you want it to be nice when you're done? Roadworthy? There's a lot more to building a cool truck than stuffing full width axles under it. If driveshafts have you stumped, good luck on the rest of the build. If you have Chevy axles and a Nissan t-case, a good place to start is with a pair of Nissan driveshafts and a pair of Chevy driveshafts. Cut the ends off and piece them together. If don't you want them to vibrate, you're going to want CV joints at the t-case. If you need lots of slip, you can find long slip parts online at places like Tom Woods, High Angle Driveline, Trail Gear or even at your local driveline shop. A pair of custom built shafts with new parts can cost you $300 to $400 each. If you bring the parts, they can be done for the price of tubing and labor, roughly $200. 1 Quote Link to comment
datzenmike Posted December 29, 2015 Report Share Posted December 29, 2015 If keeping the 720 T-100 transfer case it won't stand up to a 4.3. I'm assuming you are getting a chev trans case. 1 Quote Link to comment
Stoffregen Motorsports Posted December 29, 2015 Report Share Posted December 29, 2015 Good point. Also, a rule of thumb, the taller the gears (lower numerically) in the axles, the more stress put on the transfer case. Gear the axles to 5.29's or more and save the t-case. Chevy gears are cheap. 1 Quote Link to comment
Lakec423 Posted December 30, 2015 Author Report Share Posted December 30, 2015 Yeahh I'm fine with all the fab I just wanted an opinion and the t case will hold up just not forever I've seen them beat on pretty good Quote Link to comment
Lakec423 Posted December 30, 2015 Author Report Share Posted December 30, 2015 Btw I really precate your guys help I am doin a budget build so it will be a little crude but it's a Ratsun not a show truck and I still can't figure out how to post picks Quote Link to comment
Stoffregen Motorsports Posted December 30, 2015 Report Share Posted December 30, 2015 Good that you know what you're getting yourself into. Eyes wide open is the best policy. Photobucket is probably the easiest way to post pics. Get a free Photobucket account. 1 Quote Link to comment
datzenmike Posted December 30, 2015 Report Share Posted December 30, 2015 photobucket and ratsun 1 Quote Link to comment
Lockleaf Posted December 30, 2015 Report Share Posted December 30, 2015 In that case, I say go for it. In your shoes, I would plan on gears being my first post build upgrade. I get the whole budget thing, so just build it the best you can now, and look at what upgrades in the future will be best, both in budget and in usefulness. Start your build thread, let's see this happen. 1 Quote Link to comment
Lakec423 Posted December 30, 2015 Author Report Share Posted December 30, 2015 ill see what j can do keep y'all posted 1 Quote Link to comment
Lakec423 Posted December 30, 2015 Author Report Share Posted December 30, 2015 I wana load the pics from my phone Quote Link to comment
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.