1991 Chevy Blazer after setting timing to spec truck runs l

i check the timing to find out it was way off i had to take out the distributor and turn it to get the timing right finally got it to where it was suppose to be tdc
i took the truck around the block and it wouldnt move had no power the shifts where not right and where really hard i dont understand how it could run so nice with the timing so messed up be for to go to running like a junker