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Raising the Differential Mount... Any Pics??

4955 Views 39 Replies 10 Participants Last post by  Turbo84
Ok well next up on my list of mods is raising the diff 1" as described in the power manual. I know people say just remove the rubber bushings from the support, plate the holes, and weld it solid but pics are worth 1000 words. A custom x-member wouldnt be out of the question either. So let see some pics!
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easiest way is to cut the underside out of the crossmember and weld in a new underside 1" higher.

Next question WHY? Did you lower your suspension to the point where you need to do this to bring up the roll center to combat jacking forces and keep the halfshafts from stickinhg up @ settled ride height?????
My plan is to take the car down quite a bit. The way I see it, if I go ahead and make the cuts and I end up with the car's ride height higher than planned, all I have to do is add a spacer to even it back out. Lots easier to cut it up with the frame off than with the car back together.
I opted out on that one as I'm running 28" tall tires and I used up that inch ;) ;)

It prolly a 30 minute job with the right tools... :D :D
how about putting a batwing in as a way to lower the diff and shed a little weight at the same time?

i'm trying to remember how thick the front snubber bushing is. Probably more than an inch. I assume you would trim an inch off or just put a soft metal washer in, assuming you can raise the front without the drive shaft touching the tunnel.
Ive thought about it a lot but will it hold 550hp? I havent done too much research on the aluminum rears at all.
Ive thought about it a lot but will it hold 550hp? I havent done too much research on the aluminum rears at all.
they say the batwing will. You bolt your iron diff to the aluminum batwing.

BeeJay was supposed to try it and let us know.
Ohhhhhhh. Dont use the 80-82 diff, just the batwing. I gotcha. I dont know if that would be worth all the extra work or not though. I am a little concerned that my CG is going to be too far back with the LS6 up front moved set back 3" and all. It seems like Ive dropped a lot more weight off the front than the rear....
Front-
LS motor set back 3"
Bumper Support and Misc
Aluminum Rad
Rack and pinion

Rear-
Bumper support
Aluminum driveshaft
Fiberglass spring
????

Thats about all I can think of. Ive got wilwoods on all 4 but those cancel each other out. I wonder what else I can take out of the rear to help out...
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I wonder what else I can take out of the rear to help out...
Replace cast iron diff and removable crossmember with an 80-82 aluminum diff and batwing?:laughing:

sounds like you want to road race. Why do you need such a strong diff?

Maybe i'm wrong but i don't worry about the front/rear split. Just get it as light as possible for your application. Mine needs to stay a street car so i doubt i will ever get under 3000 lbs.
I do want to do some racing on saturdays and keep it a street car as well. The LS6 thats going in it dynoed at around 430rwhp with a 4.11 gear in a 02 vette. Im adding bigger injectors, better intake, and a different tune. I also am running 3.08 gears. I hope so see about 550hp at the crank and 460hp at the wheels. Im not going to be running huge tires on the street(285s) but would like to put some slicks on at the track if I get good enough. I figure they are going to put a hurtin on the rearend. I hope so anyway! :D
........................................................?

Maybe i'm wrong but i don't worry about the front/rear split. Just get it as light as possible for your application. Mine needs to stay a street car so i doubt i will ever get under 3000 lbs.
:agree:

You're on the money there, Turtle. I'll gladly take weight out wherever I can get it. I'll bet a lousy weight distributed, but lightweight car will beat a heavy 50/50 car everytime. I'm pulling over two hundred pounds of weight off my front end, and I'm not sweating the loss of the magical 50/50 ratio.
I do want to do some racing on saturdays and keep it a street car as well. The LS6 thats going in it dynoed at around 430rwhp with a 4.11 gear in a 02 vette. Im adding bigger injectors, better intake, and a different tune. I also am running 3.08 gears. I hope so see about 550hp at the crank and 460hp at the wheels. Im not going to be running huge tires on the street(285s) but would like to put some slicks on at the track if I get good enough. I figure they are going to put a hurtin on the rearend. I hope so anyway! :D
Hoss,

I'm building up a new frame and suspension for my '69. I'm using an '82 batwing and an iron case 3.08. This rear is sitting behind a warmed over 427. I plan on running the crap out of this setup, just like the old setup. I expect the rear to be the least of my worries.
On an earlier post you mentioned setting the engine back three inches. How are you doing that? Are you massaging the firewall significantly? Just curious. I've looked into setting my engine back, but an inch is about all I can do without serious surgery.
Its an LS6 out of an 02 vette. No distributor:partyon: I am about 1 1/2" from the firewall I would say. I could go even more but Im happy with where it is at. I will have trans x-member problems if I go back any further. I may have them now but I wont know until a week or so when everything is mocked for the last time. The Ls6 is awesome though. Shaves at least 300lbs off (400 in my case), fuel injected, great power, and it looks sooooo cool!
Its an LS6 out of an 02 vette. No distributor:partyon: I am about 1 1/2" from the firewall I would say. I could go even more but Im happy with where it is at. I will have trans x-member problems if I go back any further. I may have them now but I wont know until a week or so when everything is mocked for the last time. The Ls6 is awesome though. Shaves at least 300lbs off (400 in my case), fuel injected, great power, and it looks sooooo cool!
Not disputing your numbers, but can you expound on it? An aluminum sbc would reduce your weight by about 150 pounds (90 in the block, and 60 in the heads), but your numbers are 150-250 above that. I don't doubt that an LSx engine is lighter than a small block, but where are you getting the rest?
I was wondering that also

I wouldn't pick up much with the LS-1
I don't doubt that an LSx engine is lighter than a small block, but where are you getting the rest?
probably heavier. It has all that additional skirting material for the 6 bolt mains.
In case you didn't notice Redvetracr posted the pics
OK my orig motor is all iron. Intake, cast manifolds, water pump, ect. LS has the following alum- heads, block, oil pan, valve covers, w/p, acc brackets, plastic intake, you get my drift. Im also adding headers, losing the a/c compressor & mechanical fan, going w/ a smaller p/s pump (ls style is very small).
Now if you already have added things like an aluminum intake, headers, w/p, things of that nature, of course you arent going to get the weight difference. LS is 380lbs fully dressed. A cast 350 is roughly 550lbs bare (google search says that anyway) Add in the cast extras plus the weight I lost going to an aluminum bellhousing, flywheel, and transmission and the numbers come together nicely. If you were to just swap to the LS already having everything aluminum in your 1st gen 350 you can still pick up 200lbs.
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