seldawg

Wondering if anyone can tell me what would be better to stick in my 84 GS. I have an 83 GSL out back and have already dropped the 84 GSL-SE rear end. I just checked the archive and found out the GSL diff is stronger. Which one should I put in my GS? What are the benefits of each as far as which one is quicker off the line and which has a higher top end? I have a slightly modified 12a in the GS and am going to put the GSL-SE 5 speed in the GS as well as a heavy duty street/strip clutch and pressure plate. Are the bolt patterns for the GS and GSL the same ( 4 x 110 ) cuz that would save me the hassle of puling the axles.

cds00bsmg

iTrader: (1)

lug pattern is different between the GSL-SE and GSL. I believe the SE has a 4x114.3 pattern. Not sure why you would want to stick with the 4x110 other than to match the front end, since 4x110 wheels are kind of a bitch to find.

I can't really clarifiy on which rear end is stronger, but I would have thought that the SE rear would be since the SE comes with a higher horsepower 13B from the factory. I know the SE transmission is supposed to be stronger as well.

Archives should have a thread in there titled "Diff between GSL and GSL-SE" or something to that effect..

Sorry for help I provided you, Im sure someone can give you more details. Heh, if your interested in letting one of those LSD rear ends go for a reasonable amount, let me know...

~Chris

seldawg

I let you know if I decide to let one go. Have some kick *** wheels for the 4 x 110 pattern, that is why I want to keep that bolt pattern.

aussiesmg

iTrader: (1)

All 84/85 rears have bigger axles and bearings, SE pumpkin is no stronger than GSL but it is a 4.1 LSD and the GSL is a 3.9 LSD. I would go with the SE rear for these reasons and then look for some SE front struts to go in and match the 114.3 lug pattern. In fact this is exactly what I'm doing to my 83 GSL.

SE rear brakes are also bigger and vented....

skrewloose78

how is the gsl diff stronger? the -se axles are bigger and have more splines.
the gsl-se diff will give you better acceleration out of the hole (4.1:1 ratio)and the gsl will give you better topend(3.90:1)
the gsl-se has a 4X114.3 bolt pattern all other 1st gens have 4X110
the -se trans(i believe ) will also give you a higher 5th gear ratio to compensate for the lower rear-end ratio

seldawg

Thanks for the info. I thought about going with the SE struts so I have the same bolt pattern all around until I found out I can pull the axles from my GS and swap into the SE pumpkin. I really like the rims I found for my GS a couple year ago and they make the car look great. Downside is I won't have the SE suspension.

seldawg

SE tranny does have a higher 5th gear ratio. Not to question you cuz I am new to this rear end swap, but are you sure there are splines on the SE axles cuz I was told you can swap the 84 GS axles into the 84 Se pumpkin. Would that not be possible if there were more splines ?

aussiesmg

iTrader: (1)

84 and 85 GS, GSL and GSL SE have the same size axles.
earlier FBs have smaller.

Transmission ratios are not relevant to this post.

4.1 versus 3.9 is a marginal difference, but it is a slight advantage.

All Fb axles have splines....

skrewloose is correct except the 84/85 GSL axles and bearings are the same as the SE

'85 GSL 302

Either will work. The GSL will go right in, or the GSL-SE with your axels. I'd try the GSL-SE though for the reasons already mentioned. Do you also have the GSL axels too? The same is try in reverse, the larger '84 axels won't fit the '83 GSL diff.

Personally, I'd do the whole GSL-SE suspenion for the larger front brakes and vented rear rotors. Wheels be damn'd!!! :-)

seldawg

LOL, left out the word " more ". Axle would not work too well without splines. Maybe I am confused but I am not going to run into a problem with different sized bearings by swapping the axles of the SE into the GS as long as they are both 84's am I ? Noticed on your profile you mention Amsoil. Use it ?

aussiesmg

iTrader: (1)

SE front brakes aren't any bigger, just the 114.3 stud pattern.

seldawg

Have the GSL axles too. Have an 83 GSL, 84 SE and 84 GS at my disposal. Complete cars. got'em cheap from people who do not know the rotary. Too late to consider keeping the bolt pattern from the SE. Had to drill out the 2 screws that hold the rotor to the rear axle from too much corrosion, Took about 4 hours to get out 4 screws

aussiesmg

iTrader: (1)

When you put them back together delete those little screws they dont cause any problem, its just a way for the factory to hold the rotors on until the car is off the assembly line.

Don't settle for the drum brakes off the GS, go with the complete SE rear end.

seldawg

Maybe I will go with all SE at the wheels then. I seen a post earlier about swapping out the GSL ring and pinion to the SE diff. What do you think. I am only considering to possibly save some cash. On the other hand I like the idea of new versus used. On a diferent note. I use Amsoil in my rex and noticed an immediate difference.

steve84GS TII

Actually,the SE front brakes are bigger.....9.84" diameter compared to the 12A car's 8.94" front discs.Disc thickness and pad area are about the same however.The SE's vented rear brakes are even larger at 10.1", compared to the 12A's solid 7.87" discs.Makes for a more effective parking brake and better brake balance if you upgrade to TII, or aftermarket big brakes in the front.

From what Ive heard,the SE has 1 less clutch disc in the LSD pack,hardly any difference in strength.Axle and bearing sizes are the same for all 84-85 cars.

The SE's 4.07 final gear ratio is good for a little more acceleration over the 12A'a 3.90 ratio.Its well matched for an SE or TII tranny,but might be a little low geared for a 12A trans.(more revs on the highway)

aussiesmg

iTrader: (1)

The difference in RPM at 60 mph will be around 100 rpm, not a significant amount, I will measure my brakes but I was advised all FB 84/85 fronts are the same size rotor. I stand corrected.

Just ran out and measured them and you are right they are larger rotors, hmm my source was a knowledgeable member, shows nobody is perfect....