Need help with identifying left/right OEM aluminum motor mount brackets

[InFiD3ViL]

So I am installing my engine today and am running into a problem getting the engine to mate properly with the bellhousing on the transmission. I can get it to line up good, dowels line up, but I am left with nearly an inch of space. The rear of the crank has begun to seat into the torque converter, so i know its centered. The 6L80 was never pulled from the car and nothing from the tranny back was touched. I have it supported with a jack.

I think the issue may be related to the aluminum motor mount brackets. They came off my L99 and I swapped them to the LS3. Problem is, in all the craziness over the last 3 months with parts being all over my house, I don't know which bracket is the left and which is the right. They are not symmetrical. l meant to label them, but of course I didn't. They are definitely different though, but will bolt up without issue on either side.

The only way I can tell the difference is that one of them has a longer locating tab than the other. But I couldn't find and other identifying marks. All the parts sites shows them as different part numbers but only show drawings.

The tab I am talking about is on the upper right hand side. This is what's currently on the drivers side. The bracket currently on the passenger side has a much shorter tab. My brain is mush right now. Long day. Thanks guys.

[Bo White]

I think they only go on one way and sit flush.

[InFiD3ViL]

Well, I guess I will know for sure shortly. I am going to lift it back up and see if they will swap sides and then try to reseat it. Shouldn't take but a few minutes. I ran out of daylight and motivation last night.

Sometimes it is best to walk away from a project and come back the next day with fresh eyes.

[InFiD3ViL]

Originally Posted by Bo White

I think they only go on one way and sit flush.

You are 100% correct. They are in the right way.
I have a 1/2 inch gap between the engine and the trans right now. Not sure whats going on. The crank is seated in the hub of the tq converter, but obviously not fully.

I have tried altering the height of the tranny and the engine and angle...I am at a loss. Could the trans have shifter back a little bit on the driveshaft yoke? Time for a break.

[chevyz1]

Make sure your torque converter is seated in the front pump and not sticking out. If it worked forward and not seated in the pump, you could crack the pump in the tranny. That would cause you to not be able to mate the the block to the housing all the way.

[InFiD3ViL]

Yeah, I better make certain its fully seated. Out it comes again. I know the jack hold my trans up leaked a bit and when I went out the other day the front of the trans was leaning down.

[InFiD3ViL]

Originally Posted by chevyz1

Make sure your torque converter is seated in the front pump and not sticking out. If it worked forward and not seated in the pump, you could crack the pump in the tranny. That would cause you to not be able to mate the the block to the housing all the way.

OMG man, you are a lifesaver. So apparently the TQ converter DID indeed slide out a bit when the trans sagged. It moved back nearly an inch and made sure it was fully seated. Afterwards I measured the bellhousing to bolt pad depth and it was right within range. Trans and engine are now together.

Thanks so much man.