This is probably a very simple solution that I’m overthinking. I have a spare 3rd member 4.10 (open diff). In my front axle, I have a 4.88 3rd with a supra LSD that I bought a long time ago. If I buy a spartan locker, or any lunchbox locker, I should be able to use the carrier from the open diff and the lunch box locker to replace the LSD, right? A lunchbox is much cheaper than buying a yukon or something similar.

 

Is the spare 4.10 diff also a front IFS diff? I don't know the answer for sure. I'd maybe compare the part numbers of the carrier bearings between the two. Be aware that installing a front locker in an IFS truck with stock axles might start breaking those axles if you really use them in extreme conditions. Even the straight axles with lockers break the stock birfs easily.

IDK if Zuk (Ken Francisco) is still answering emails but you can try. He would probably know for sure. gearinstalls@gmail.com

 

Forgot to mention it’s SAS’d. Theyre both 4 cyl diffs. I did some more digging this morning and I don’t think I’ll have an issue since theyre both 4 cyl. May have to buy some longfields if the mrs allows.

 

I think the only time you might have a problem was with the 4.88 factory geared diffs in the1992 to1995 V6 trucks that had 31" tires from the factory. If it's not one of those and both the ones you have are 4 cyl diffs you should be good to go.

I have Aussie Lockers in my V6 4 pinion diffs and they are definitely different than the Aussies I put in my son's 4 cylinder diffs with the 2 pinion setup. So the lockers themselves are different for the 4 cylinder VS V6 8" diffs. Good luck with your project!
Scott in AZ.

Catch the Longfields on sale if you aren't in a hurry. Summit Racing often has them with free shipping even though they will come directly from Trail Gear.
RCV axles are better but more money. I have been running Trail Gear Dirty 30's on 35's for MANY years and so far they are still holding up. Don't forget the Chromoly hub gears if you want your warranty on the axles.