I just get a 19" dif. wiht 3.5 gears for my 1970 sportroof, ¿What changes can I expect? the dif I took off the car was an stock one
Thank You

 

19 or 9? 19 would be terra truck size.. or thereabout..

it depends on what stock was. If you have an 8" rear, the 9" is stronger but maybe the 8" isnt in danger if you have a small engine. not enough torqe to break either one. If you have 2.70 gears and switch to a 3.50 gear, you will see a difference in mileage, cruise rpm, acceleration, and it will probably spin the tires much easier but not as far as the 2.70 would

 

Just in case he meant 19 cm, that's equates to ~ 7.5".

 

I was gonna say....Man, that 19 inch rear must be off a tractor or something.

 

Sorry is 9" my engine gives about 350HP
thank you

 

an 8" rear would still work fine at your power level. But if you have the locking type diferential in the 9" and an open in the 8" (if you have an 8" that is) then its a good swap. wont hurt at all to have a largeer rear back there with a bit more gear.

Without knowing what gear and rear you have now, and the engine specs (especially the camshaft specs) its tough to say what you can expect from the swap. But pretty sure you will enjoy it.