i was wondering what the rear-end of my '89 power ram50 4x4 could take before breaking. i'm planning on putting a 300 cubic inch 1992 4.9 liter caddy motor in it instead of another 2.6. just wondering if the stock rear-end can hold up to it is all.

It should be able to handle that motor; Is it a northstar v8?

So far it shows that it holds power from the 4g63 turbo motors for more then 300 horsepower. But of course the 4wd LSD rear end in the mongrel, ram 50 and mightymax trucks may hold it better then the open diff. I'll second that it should hold the power of that v8.

its not a northstar motor. i think its a year or two before that. i plan on using a MS2 ecu to run the motor with a turbo350 tranny. i'm turning this 4x4 into a two wheel drive. it'll slide better on the back roads. thanks for the input on the rear end. good to know it will hold up.

I have seen the mitsubishi 8 inch rear end hold up to 500hp

Just use what you have. It should be fine for now. Te only reason I sued a Isuzu Rodeo for my truck is it was only 4 inch wider and comes with disc brakes and drumb parking. You also get a Dana44 that has a huge amount of options. From Air lockers to full lock.

If you're really worried about the power, swap an a-body mopar 8 3/4 axle under it- thats good for all the way up to 440s and hemis, and gives you 5x4 1/2 bolt pattern as well