chevysquid

iTrader: (7)

has anyone does the blazer brakes swap yet that can validate this works?

thmpsn70

I did it on a vega did quite a write up on it too the only real difference in the 2 is the vega housing is narrower than a camaro one, here is the link I am cosworth0135 on there there is a parts list on page 5 or 6but keep in mind this was for the narrower vega but the info is still good info the parts should be the same not including the axle shafts. Timmy

1983Chimaera

I did the 4th gen rear end swap when I first got my 1983 Z/28 on the road. Mine is a 1995 Z/28 rear with 3.23 gears, limited slip and disc brakes, and it bolted right in. I did have to adapt the older SAE brake line fittings on my car to the 4th gen metric fittings, but anyone with a later model 3rd gen shouldn't have this issue. I used the 1995 parking brake cables and used hose clamps to attach them to the parking brake guides on the underside of the 1983 body. It's been in my car this way since 2007 with 13,500 miles on it now with no issues. I also changed out my proportioning valve for one off of a rear disc equipped 3rd gen Firebird. As for wheels the guy I bought my rear end from threw in a set of 4 4th gen 10 spoke 16" alloys for $80, and I only paid $300 for the rear.
As for why to do the upgrade in a daily driver, well, you gain a limited slip differential, larger disc brakes than are available in the aftermarket conversion kits and for less than half the cost, it's a direct bolt in, and the early 4th gen cars are starting to become more common in the junkyards as they age and their values drop due to the new Camaro, so upgrades are there for the picking. It's more a question of why not?

flyitlikustolit

I agree totally. best upgrade for the money I ever did to my 3rd gen besides the wonderbar.

1983Chimaera

I lucked across one of those last summer at the local Pick N Pull here and installed it. Haven't noticed a difference yet (my car croaks, groans, and rattles all over...it's had a hard life!), but I'm running 4th gen 10-spoke alloy rims on all 4 corners, and the bar was specifically made to counter stress problems with running wheels larger than 15". That, and since the backspacing on the 4th gen wheels is so much more than the 3rd gen, the 2 1/2" adapters I have on the front spindles has got to be putting extra stress on the front suspension geometry and subframe. Hopefully it's doing its job and keeping stress cracks from forming. Next step is to fabricate a strut tower brace that triangulates with the firewall but doesn't interfere with the TPI intake or HEI distributor, and make some subframe connectors with bracing under the front seats.

Pats91Z-28

Whats up everyone. Had a quick question about the swap. Just purchased a 2002 rear from a firebird trans am. My question is will i use the 3rd gen panard bar or the 4th gen panard bar, or are they the same lenth? Thanks

Orr89RocZ

iTrader: (20)

They are the same thing. Might as well keep the thirdgen one since you dont have to remove it to get the rear installed.

tylercamaro

iTrader: (1)

how about torque arm, can you use the 3rd gen one, or is 4th gen preferred. im planning on running a 4l60e later on too so idk which would be better. great info though

Orr89RocZ

iTrader: (20)

Use your thirdgen one as its easier to work with since its already connected to the trans. They should both be the same if using automatic torque arm from either year. 6spd 4th gen one is different.

92firebird 305

i got a 4th gen rear for my 92 firebird its out of a 98 ls1 6 speed its got the 3.42 posi disk brakes im going from a 2.73 open drum to a 3.42 posi disk should i have any problems with the switch and i have 15 inch rims i know its gonna be 2 inches wider on each side i have a 305 tbi with 202 hp and 268 tq i hope that my rear swap makes my car jump off the line better

Orr89RocZ

iTrader: (20)

rears are same as far as hook ups go. Read this thread to get the details but if the 4th gen brakes are 3 channel it will bolt to the factory body line on the car, at the t-block on the rear.

15" wheels wont clear the LS1 calipers without alot of grinding to the caliper and maybe even a spacer.

92firebird 305

i been told by a lot of people that on the rear it will fit

Orr89RocZ

iTrader: (20)

what will fit? The rear will fit in just fine...its a bolt in, but 15" wheels wont clear LS1 calipers, well atleast most 15" wheels wont clear without grinding. You'll have to see. The brake lines need to be 3 channel stye to work and adapt to the stock 3rd gen body brake line single connection. 4 channel ABS/traction control rears have 2 brake lines off the rear end, each going to a separate place. 3 channel are not traction control and they meet into 1 connection on the rear to attach to the body's hardline

92firebird 305

well im having a shop put it in thursday for 120 and the rear is out of a 98 ls1 camaro with 6 speed it does have the abs senor but nuttin else and my ebrake done work now so im just have then cut that line off

Orr89RocZ

iTrader: (20)

Just need new e-brake lines. Some part numbers are listed in this thread

87CamaroIrocZ

im going to do the 4th gen rear along with lowering the car with sportlines should i be worried about tires rubbing on the fenders when lowered i just have a feeling it will happen

92firebird 305

no it should work fine i did a 4th gen swap on my 3rd gen and i have 15 inch rims and it worked out fine

92firebird 305

i did my swap with no problems and i have 15 inch rims no rubs on anything at all mad a big difference from a 2.73 open to a 3.42 posi now i just gonna get my speedo fixed its on a 92 firebird

scorp88

I just got '93 donor. Can I keep the prop valve that's on 93? Everybody here talking about using one from disk brake 3rd gen, but if calpers are the same, why not keep one that's on 4th gen axle?

Orr89RocZ

iTrader: (20)

The valve should be on the 4th gen car's master cylinder and not on the rear end itself. You can use the 4th gen master cylinder but not sure how the lines are run on those cars. If they bolt up to the thirdgen hardlines, it should work. The PBR brakes on the later thirdgens should be same as the LT1 cars from my understanding.

scorp88

Aaah, I didn't think about that. Have to take a look. There's a big switch block connected to '93 master from what I remember. ABS/TC? Other then that it looks prety much the same.
Is that big spider looking thing a prop valve? Sorry for blurry pic. made with phone

72vega

iTrader: (9)

they are. i have an 87 GTA that i swapped a disc rear from a 97 z28 and i got e-brake cables for an 89 or 90 to hook them up and it was a direct install. no using cable clamps and stuff to make it work. also i used the LCAs, panhard bar, torque arm and sway bar from the camaro, all bolt on/no mods to install them. (everything but the torque arm were hotchkis parts)

scorp88

Would this be a good prop valve? I know it's for 2nd gen, but looks like plug and play.
http://www.ebay.com/itm/220688455701...84.m1423.l2648

reride

iTrader: (1)

Orr89rocZ, Great thread you started here!!

Your orig. thread stated the differencies between 3 & 4 channel 4th gen rears, as far as the brake lines go. But as my luck would have it, I have come accross a hybird.

I picked up a rear from a '94 Z-28 w/a sensor in the center section (4-channel), yet it has t-block (3 channel) that ties the two calipers.

I have an '89 iroc and wondered if you might know if the single flex line from the body would have threads that match the t-block?

I'm triing to have all parts together before I make the swap.

Again, your thread provided alot of useful info! THanks

72vega

iTrader: (9)

since it has the normal single rubber line, it will work. just reuse the rubber hose from the 94 and screw in the hard line on your car. the rubber hose does not unscrew from the splitter. it is crimped onto the hose.

WildBillyT

Sorry to raise an old thread but I've got an interesting question.

Are the hard lines on an 89-92 J65 rear disc third gen the same as a 93-97 3 channel f-body?

Orr89RocZ

iTrader: (20)

Not 100% sure but sounds like somebody may have played around with that setup but the single flex line from the body should mate up to the rear ends T-block.

They probably are different length due to different length rear end sizes. I do not know if the end fittings that are on those lines are the same or not..but that shouldnt matter. If you use 4th gen rear's with 4th gen brakes, then the 4th gen lines should be considered.

watajob

iTrader: (29)

Get a hold of Ed. He's got this on lock-down. No matter the gen car or rear. Any combo. Screw the 2 ends in, bleed. You're golden.

GMan 3MT

iTrader: (4)

Am I reading this right in that the 3rd gen auto, 3rd gen 5spd and 4th gen auto are identical and the 4th gen 6spd is different? What's different?

I have a 4th gen rear and T56 to go into a '92 drum/T5 car. I was planning on baby steps, do the rear end first, sort out any bugs, and a few months later do the T56. I thought all the torque arms are the same. I have no desire right now to go aftermarket, but do want the 'best' factory one.

Orr89RocZ

iTrader: (20)

I think the arms are all the same however the arm mounts on the tranny are different for autos vs manuals. T5 and t56 use same mount i believe.

skip91

Getting ready to do the swap and will be inspecting and cleaning the rear before the install. This will include replacing the differential gasket, gear oil and posi additive. What weight gear oil do I need to use?

skip91

Got the rear end yesterday. Going to clean it up and paint it with POR-15. Should be getting installed within a week.

Orr89RocZ

iTrader: (20)

I used a basic 80-90 weight oil. Nothing special.

skip91

Thanks for your time and information Orr89RocZ.

Nyczbubba

Okay I've read through about 8-10 threads about swapping 4th gen rears and working the parking brake. I bought a 92 camaro with a 94' rear in it already with no parking brake. The rear calipers are missing the attachment on the calipers to the parking cables and also missing all of the parking cables. So I'm buying 2 new rear calipers for a 94 camaro. The rear are disc brakes. So I need to buy a whole new cable assembly to install. A 91-92 parking brake cable would work fine on this? Can anyone link me to the full assembly needed or give me part numbers?

go88iroc

So if I'm swapping my 3rd gen drum rear to a 4th gen disc rear what do I need to do with the brake lines?

Orr89RocZ

iTrader: (20)

I know this is late but LT1 cars should have same calipers as a 89-92 pbr disc rear car. So a 91-92 cable should work

A disc rear to drum car should just need the 3 channel lines as explained earlier. Single line on the body of car right? That should bolt to the single connection on rear. So only other thing to consider is a disc proportioning valve but some report drum valves work ok

zenish

just use all the lines that come on the forth gen rear.the third gen brake hose bolts up.its all bolts in without alterations.the only thing that won't work are the parking brake cables.

1983Chimaera

Not necessarily true. The earlier 3rd gens still used SAE brake line fittings, whereas later 3rd gens and all 4th gens used metric fittings. If your car is an SAE car, you can either use an adapter fitting to convert from the car's SAE fitting to the 4th gen rear's metric fitting, or cut off one of the two fittings and replace it and reflare the end (the more complicated option). I did the former to put a 1995 Z/28 rear with metric fittings in my 1983 Z/28.
Be aware you also need a 4-wheel disc car's proportioning valve, or an adjustable one like a Wilwood. I used one off a factory 4-wheel disc 3rd gen Trans Am.

-srs-

OK. After reading through the threads thus far, this is what I have concluded. I've got a 91 Z28 vert (305) A4. It is most likely has 2.73's though I haven't confirmed this. From what I gather, what I am looking for in order to get the best seat of the pants kick would be to find myself a 99-02 3 channel rear from a T56 car for a few reasons.

First, it will have 3.42's which should give me a much more responsive feel on the low end without being undriveable on the highway.

Second, although wider than the stock 3rd gen, it is not as wide as the pre-99 4th gen rears.

Third, the calipers will likely NOT have to be ground in order to fit inside my stock rims.

Am I on the right track here? I'm not in a hurry since I've got some other things to tackle on the car but I can start the search for the rear now and be patient for a deal. Comments? Suggestions? Thanks!

Mr.ChevyStroker

i'm with -srs- here, I have factory 1991 305, 3.08's open drum diff, and wc t5 andd looking for a 4th gen rear end, luckily a guy is shootin me a deal with a 3.73s with hotckiss trailing arms,( i think he meant torsion bars? Any who, it will come with the master cylinder for 350 bucks. Channel 3 is the one i am gonna be looking for, and I already have 16 in stock wheels so clearnance shouldn't be an issue. and sway bar will fit from my car along wit shocks, springs, etc.

tylercamaro

iTrader: (1)

we dont have t bars lower control arms or trailing arms is correct

Orr89RocZ

iTrader: (20)

I just picked up a 98 rear with 3.08 gear. Hope its a posi. It is 3 channel with disks. After i finish stripping rust and painting it, and get new brake parts, i'll be swapping it into my drum rear 91 Z28 car along with a 4th gen plastic gas tank

Mr.ChevyStroker

Okay the trailing arms is a good steal considering they're like 300 new correct?
And the master cylinder should be able to help without the prop valve also? or should i get one along with the master cylinder?

Orr89RocZ

iTrader: (20)

Lower control arms or trailing arms could be 50-150 new.
Master cyl wont change much with out the proportioning valve

Mr.ChevyStroker

Are the lines the same on a 4th gen ls1 prop valve from a sstock rs? And maybe ill give 400 for the rear end trailing arms master cylinder prop vavle and the aluminium shaft... but still waiting if its a 3 channel or not

87zeder

trying to do a search on if you can swap a 4th gen v6 rearend into a 3rd gen but all I'm finding is v8 z28 swaps.. I found a posi 3.8 one and I've broke down the vin it does have the disc rear... is there any difference in the v6's compared to the v8's??? or is it basically the same? I've already read the thread on the swap itself so I know the ebrake and proport valve I will need just curious on the 3.8 v6 rears

JamesC

iTrader: (5)

No.

Yes.

JamesC

87zeder

awesome thanks a lot james!!!

Night rider327

iTrader: (13)

Same goes for third gen and 4th gen cars, heck even second gens.

The same rear end was used with all engine combos, the only difference will be the gear ratios.

Most of the time the 6cyl cars got lower gears to make up for lack of torque from engine. So truth be told, for a performance based build it may be best to start with a good 6cyl. car rear end.

82-85 7.5", 26 spline axles
86-90 7.625" 26 spline axles
91-02 7.625" 28 spline axles