This should be a good first post!

I just poped the spider gears in the factory 12 bolt, took out the spring plates, recoiled the springs, and nicked up the pinion and ring and a couple of chips here and there. The clutches have a little black discoloration, not bad but probably should be replaced in the rebuild, if there is one.

SO, Does anybody make a posi that will hold up or would a spool be the answer or even an aftermarket rearend with one or the other. I have never driven something with a spool, but I would think if you drive like a sane person on the highway you would be o.k.

I drive 50/50 street strip so streetability is very important to me.

The specifics are 70 chevelle 4100# w/driver, 900 hp BBC, 400 trans, MT 325/50 drag radials. Best 10.24 1.74 60ft, 131mph in the 1/4, but more spray and slicks are possible.

All this, just trying to stay up with Bob West

:D Nice to have the competition :D Is that what happened Friday night Greg? I would definately go spool in your car, I had a stock posi, upgraded to a 400lb eaton posi, and now a spool. Its not that bad running around town either.

For 50/50 street strip ,don't use a spool.

Wow, you joined in august '05 and this is your first post?!?! You're never gonna catch up with Bob at that rate...

yes, Bob, saturday midnight drags were my first breakage. What did you not like about the Eaton?

If you break an axle with a spool, you will probably make an abrupt, unanticipated, sharp turn. Sometimes, that can be dangerous and costly.

Get the good, softer, spiders. Polish the tool marks out and bead blast them. If you get rid of the stress risers, they hold up pretty well. It takes an 1/8" mounted wheel and some patience.

Can anybody keep up with Bob, on posts that is. I read a lot more than I post.

The Eaton was fine, but as the power level went up, the posi couldnt handle it and I went spool, mainly cuz I race full time. I do think that Bill Burke is running one of Eatons 800lb posi's, lotsa street miles and alot less track time than myself, maybe he'll chime in. There are folks on this board that havent belonged as long as I have and have a few more posts than myself ;)

As fast as your car is going to be as you keep tuning, I think a spool and 33-35 spline axles is the way to go. I do like my Moser 12 bolt, alot beefier than a stock 12 bolt, but I have had to put 2 sets of rear gears in it already after playing with nitrous, took the nitrous off and added Richmonds Pro Gear and all is good so far.

Have recently installed in my Eaton posi 800lb springs, studs instead of bolts & steel clutches vs ceramic and had some concerns about streetability, especially around corners. So far this year I am happy on the highway and cornering. Nothing out of the ordinary. The rear end does seem to have more bite, but maybe that's the new 540.
After a few runs at the track the ceramic clutches would slip so I went to steel.

12 more posts and Bob will have 10,000 posts.
Is there an award?
Gold membership?
Or is he on steroids? (same trainer as Bonds) There should be an inquiry.
I enjoy your posts Bob. Keep it up.

Greg,
If you are looking for a spool I have a brand new 12 bolt strange spool and clip elim kit in the garage I was getting ready to put on ebay I think its for 33 or 35 spline axels PM me if you are interested, I will check the specifics on it when I get home.

I would go with a detroit true trac.No clutches to wear out.and works perfect on the street.

Greg,

I blew up the side and spider gears in my stock 12-bolt a few months ago when I finally hooked my ~700 SBC in a 3650 lb '71 Chevelle.

I replaced it with a Moser 35-spline spool and axles.

I Run a spool in my 71, 4:56 gears, slicks at the track, M/T sportsman pro's on the street. It's a little different feel on the street than a posi, the suspension and chassis will load more, but once you get used to it it's no big deal. The biggest problem is if you ever have to push the car, once the tires load, you better have a few people helping or it just stops. Also be careful if getting on it, If you set it sideways there is nothing to let the tire speeds diferentiate(differential) so the tires have less of a chance to grab, and can get real scary real quick, especially if the roads are wet.

I'm surprised that nobody has mentioned a Detroit Locker here yet. If you want something durable that will hold up to 900 HP, and that doesn't have any clutches to get fried like limited slips do, then you should consider a Detroit Locker. It still has a differential action around turns, but w/out the use of clutches. And I'd be using 35 spline axles if I were you. And I sure hope that you don't have C-clips since that would be very dangerous at the power level that you're at. Sorry if I'm stating the obvious. I realize that you probably know that, but better safe than sorry. Just lookin out for ya.

how well would the strange dana s-60 hold up? just more options i guess!!

how well would the strange dana s-60 hold up? just more options i guess!!

I have the Strange S60 Rear End with a Detroit Locker, 35 Spline Axels, 1350 U-Joints. Strange told me it was good for 1200 HP! Great on the street too.

:D Nice to have the competition :D Is that what happened Friday night Greg? I would definately go spool in your car, I had a stock posi, upgraded to a 400lb eaton posi, and now a spool. Its not that bad running around town either.

I drove on the street with a couple of spools and hated it. You try to find parking spacers where you do NO have to turn sharp. Backing and turning is another experience.
No I would definitely not drive a spool on the stree.

Unless you do a Detroit, I'd go with a spool, 900hp will need it.

I have the Strange S60 Rear End with a Detroit Locker, 35 Spline Axels, 1350 U-Joints. Strange told me it was good for 1200 HP! Great on the street too.That's^ exactly what I have for my street/strip car and the reason why I chose it was because it seemed to me that it's the most durable rear that you can buy for a car that will actually be street driven, and alaso see some strip outings.

Once Greg gets that beast off the line, it is going to be wicked fast. I can run with him now....barely :D He's run quicker, but I'm more consistent ;)

I have the Strange S60 Rear End with a Detroit Locker, 35 Spline Axels, 1350 U-Joints. Strange told me it was good for 1200 HP! Great on the street too.

So, CMT, you like the detroit on the street? It looks like the most expensive option to get, but if it holds up without problems it may wind up being the cheapest in the long run.

Is anybody having a eaton or yukon posi even holding up to 1.50 60's or better? I am obviously under achieving when it comes to 60's right now. Trying to get better wieght transfer when I hit it.

Thanks for everybodys input

So, CMT, you like the detroit on the street? It looks like the most expensive option to get, but if it holds up without problems it may wind up being the cheapest in the long run.



Yes it works fine for me on the street. I have no popping or strange noises from the rear end, but the exhaust is loud. I got that set up because I knew I was going to up the power level at some point. I have had no issues whatsoever with about 50 Dragstrip passes and 1500 or so street miles. The car consistanly 60fts. in the 1.62-1.65 range, so it has seen some abuse launching my Heavy 2-ton Barge. I thought it was the best option for street driving and performance at the track.

Tom Baird uses one of those power trax lockers into the mid/low 10's in his Monte.

If you want to buy tires alot and come close to losing it when the road is damp,,, just use a spool on the street...

I run a Moroso brute strength unit (Eaton) in my sons 70 Chevelle with no problems and it 60's in the 1.40's.I am planning on a spool in the future though as I only have 30 spline axles.
Vinny

If you want to buy tires alot and come close to losing it when the road is damp,,, just use a spool on the street...

Try to drive anything pushing 600hp+ on the street on damp roads whether its posi or spool you better know what you're doing and tires ain't gonna last either way :D

Try to drive anything pushing 600hp+ on the street on damp roads whether its posi or spool you better know what you're doing and tires ain't gonna last either way :D

Heck driving on dry pavement on the street is hard enough :D

how can you tell which dana is which ? the 44,60,50 etc.