I recently replaced the stock engine with a similar engine from blue print engines. Everything bolted right up. The brace bars that are supposed to go from trans to engine have no place to land on the engine but they look like they could land on the motor mount bolt but thy are about 1 inch short. I had some guys help me and nobody remembers where they went. Perhaps old stock block had a mount? Old block is gone so no way to check. Any advice would help. Some say they are needed and some say they are not. It is 4x4 automatic please advise. Thank you

 

It's been a while since I worked on one of those, but I think I remember them going to the motor mounts. Not necessarily to the same bolts that hold the mount to the engine, though. I thought there was a separate bolt hole.

Are you using the same mounts you took off? Are they on the same sides they came off of?

Sorry I don't have a better answer for you.

 

There should be a plate between the motor mount and the block that had a tab on it for the bars to bolt to on either side.

The image below shows all of the parts on an '88 K5 which is all I was able to find readily, but should be the same as your '89:


'88 K5 Blazer Engine/Trans Mounting - image screenshot from nemigaparts.com