Hi my 4.3l motor in my 99 blazer is shot and it has an automatic tranmission i need to know if i can put in another 4.3l motor that came out of 2000 s10 5 speed standard? Will tbe transmission have tbe same bolt pattern

 

Yes, it will work fine. Check to make sure the pilot bearing has been removed, or at least won't interfere with the nub on your torque converter.

 

Awesome thanks f or ur time and input i feel alot better now because that was brought to my attention after i purchased it already

 

You will need to change oil pans and oil pickup tubes if there is any difference in the oil pan. Other than that you are golden. Oil pan is part of auto trans mounting for certain. Not sure about manual trans bellhousing mounting.

 

I didn't even think about that. I put a manual transmission in mine, but it wasn't the "normal" one, so I wouldn't know for sure if there are any fitment issues. Hopefully not.

To the OP,
If I were doing the job, I would probably reseal the replacement engine before installing it (oil pan, valve covers, maybe intake manifold and timing cover), whether or not you have to change the oil pan. They're notorious leakers, and it's never going to be any easier to replace the gaskets than when you have it on a stand.

 

Good advice!!