You can find the gear ratio #s stamped on the top forward part of the passenger side axle tube near the center section,Not 3:73 etc. but the actual # of teeth on the ring and pinion I have found them there on 6 different early S10 rears since the Chevy Parts department guy clued me to this location.There are also other codes for a posi besides "G" Codes "G" being the most common unfortunatly I lost the list he gave me.My son has built several V8 S10s and hasn't had any rears fail with mild built small blocks even using them for towing and he beat on them plenty !
S10 rear codes I've used: Look in your glove box for one of these RPO codes. GU4 = 3.08 GU5 = 3.23 GU6 = 3.42 GT4 = 3.73 GT5 = 4.10 HC4 = 4.56 G80 = Posi Had to search a little bit to get a 3.73 and posi for a friend's car. Ended up with one from an 4x4 Olds Bravado (Olds Blazer). The Bravados tend to have more options than Blazers. Usually they were sold to people with more money. The Bravado that gave up its rear had stickers from a doctor's parking lot.
heres what I know s-10 trucks 2wd are the narrowest ( wont fit ) 2-10 blazers are in the middle ( will fit ) s-10 4x4 trucks are the widest ( will fit ) alot of monte carlo guys are using the s-10 rear cause there easy to find and they say there an upgrade from the stock monte rear. I think there main reasoning is the deeper gears. as for strenght we have an s-10 with a blower on a full built 383 it pulls the front tires about 10 inches, it has a stock rear end ( has gears and locker) now that said, we are pushing it. we know the trick is to keep it in a straight line when you stand on it, drifting of other moves that will transfer the power to 1 wheel quicky will destory it. there pretty tuff little units and cheap and easy to find. you will have to move the spring pads out and drill the spring pack, at the least grab the s-10 rear now and keep an eye out for a stronger unit later. I hope this helps, just measure it to be certin. MrC
If you are going to use lowering blocks, why not grab a bit of 2x4 box section and make your own spring pads. Then, instead of drilling the spring location in the centre, drill it offset by 1 1/2". Bingo, you're done! Cosmo
Hey man, just noticed your in FL as well. Where abouts? I'm near Orlando, always nice to have friends with similar interests around.
Okay, so I just measured the rear end, from inside to inside. It's freezing here in FL so I didn't have time to take the tires off and jack it up but the inside to inside dims are 54", unless we are talking measuring mounting to mounting for the wheels or something else, I have a 54" rear end.
Somebody must ask this at least once a week. Rearends that fit 49-57 Chevrolet cars: (most will also work in same years Pontiac and Olds, all have the same spring and perch spacing). - 55-57 Chevrolet. Spring perches a tad narrow for 49-54 but can be used as is; 59-64 center section fits for better gears - 55-57 Pontiac/Olds. 57 is stout, particularly if a 59-64 carrier is adapted, but they can be pricey and have a 5x5 bolt pattern. 49-56s are weaker, but will work with a mild motor. - Second-gen Camaro/Firebird. Bolts right in if you drill a new hole for the locating pin. 10-bolts have a variety of gears and disc brakes available. 4 3/4 pattern, but can also be changed to 5x5. 61.5" wide is just slightly wider than stock, can cause issues fitting skirts and clearing wider tires. Available with a true limited slip carrier. Given they came in trucks with a locker, you can probably put one of those in if you want also. - 75-79 Nova and clones. Supposed to be the same as the second-gen Camaro. No hard data on that. - S10 4x4 only. 60" wide is the same as stock. Perches need to be moved. Wide selection of gears. 4 3/4 pattern. Uses a locker rather than a limited slip, those can wear out and I've seen where people have actually blown them up too. 2WD S10 is too narrow. I've read that the first-gen Camaro is an easy fit, but those don't exactly grow on trees anymore given their popularity to restore or rod themselves. Same deal for the 68-74 Nova and clones - also supposed to be a good fit. I believe both of these need the perches moved to work. Most other mid-80s GM cars will fit under the fenders with tires on, but use trailing arm suspension so you're on your own for perches. As for making them fit, Speedway sells a Mopar perch set for about $15 that has three holes for various pin positions. Fatman has a lowering block and swaybar kit that lets you bolt in the Camaro rear. You can make your own lowering blocks with the pin hole offset at the bottom, too. Depending how much money you want to spend, Posies has lowering springs with a centered pin and Walton has a whole kit with new springs and hangers to go under the rear of the 49-54 Chevrolets.
After this comment, I decided to go look at the 68 Camaro rear end. It's the same size!!!! So I went ahead and bought the 68 Camaro rear end! I'll keep everyone updated on how difficult or easy it is.
I used posies super slide springs which relocates axle in wheel opening and lowers 3" at the same time, and to that a chevy 1956 axle. Worked perfect.
Rear ends out of 78 through 87 Malibu, El Camino, Cutless, Regal, Grand Prix, and Monte Carlo are 58 inches from hub to hub. These are nice fits for that slightly narrower rear. The Camaro 10 bolt and S10 4X4 Blazer are 60 inches Hub to Hub.
I've got a 54 Chevy hardtop and am swapping out the old rearend. Everybody seems to say get one from an S10 or Blazer. I found a rearend with discs from a 98 Blazer 4x4 with codes GU6 (3.42 gears) and G80 (Gov Lok). The width is between hubs is about 59.5", which should be fine. But, the inside width between the calipers is 44.75". The frame rails are about 47" wide on the outside. The calipers won't clear the frame. Do you have to notch the sides of the frame to clear the calipers or is this an oddball rearend with bigger calipers? Thanks
but, unless whoever you are getting rearend from has the glove box (where the ID codes are located - you can info on those from S10forum.com) from the Blazer you will need to pull cover plate to figure out gear ratio.
Pretty sure it was a 4x4. Had a transfer case and a 4 by switch on the dash. I yanked it from the truck. The glove box sticker showed GU6 and G80
unsure about disc brake rearends. maybe the calipers are to wide to fit. mine is 4x4 drum and fits great.
peter , do a intro on the new to hamb page. then start a new thread asking about disc brake rearend. also might try search feature.
Here ya go. WMS to WMS, you will need to adjust your spring perches/saddles 2wd 54.5" 4wd 59" ZR2 63" The ZR-2 rear end is harder to find but has the bearings from a 1/2 ton truck and can also have rear disc brakes.
Also keep in mind, if you run the wider rear end you may not be able to use standard offset wheels. I have standard 15x8 with a 4inch backspacing on my s-10 blazer rear and clears fine. these wheels would not have fit with the wider axle. these are 15x8 on the front to. Godspeed MrC.
The 2wd rearend is too narrow. I have a 91 s10 4x4 rearend in my 41 and there is just enough room to mount my wheels with stock rims off a '81 malibu.. I did not buy new perches..I removed the old ones,,narrowed them 1" to fit my springs and welded them into position.
so the cars and trucks are the same i take it like I said I have a 53 210 2dr thanks for your help better start looking for a 4x4 rear
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