suggestions rear end

[CliffS]

I'm looking at the last upgrade for my '68 Bird (406/400 making 425/450). It has a non-locking 2.56 diff. which I want to replace with a 12 bolt, limited slip. What do I have to look for; brand street race gears,spline,axles....any advice?

Thanks,
Cliff

[chicane67]

12 bolt housing, perferably a 69 multi leaf.
US/Strange gear set, ratio of your chioce.
Eaton limited slip differential.

Axles......well here is where you have to ask yourself a few questions. Stock replacement (which will work fine for your power level) or an aftermarket set that has press-on style axle bearings. Next, is this a drag race chassis? If so, NHRA requirements state what is needed....(and I will not recommend "C-Clip" eliminators) but there are quite a few companies that do kits just for this, that come with bearing cups that have to be welded on, a set of axles with presson axle bearings, a set of axle retainers and the associated hardware.

If it were me, at that power level and I didnt have the BIG budget, I would get a set of replacement 30 spline axles from Tom's Differential in Paramount California. Cheap, stronger than any factory axle and with some great options like two bolt patterns, two wheel studs sizes and/or types.

Next in consideration would be a set of axles from Mark Williams. Stay with 30 splines. His axles....you will never brake. Period. The best part is that the kit price for his axle's runs right about $400.00 total. Then you will have the assoicated labor of welding the new ends on and strightening the housing....paint and assembly.

Anything else, ask away........that's why we are here.

[CliffS]

Thanks for your input Chicane67!!

Correct me if I'm wrong but those first gen 12 bolts are hard to find especially when you're in Europe (Amsterdam, The Netherlands). So I am looking at aftermarket stuff. I called Moser yesterday and this is what they advised me: 12 bolt (multi leaf, I have the Hotchkis lowered leafs), Eaton posi, 30 spline axles, street gears and ford 9" end housings! They will send me a quote for parts & shipping in the next days.....

[dennis68]

Cliff, I really don't endorse vendor bashing because even I have my bad days. I have however on more than 1 occasion had-------unhappy experiences with Moser as have several associates in the trade. I suggest shopping the market before deciding on such a major purchase. A 12-bolt with 9" ends (NOT c-clip eliminators) with a good clutch type posi will work very well for many years.