I just dropped in a fresh SB and my converter to flexplate clearance is now less than .01".Seems too tight to me,correct? The only part replaced was the block and with the previous block I had 1/8" clearance. I'm sure someone has run into this before and thanks for any help.

Sounds like the converter isn't seated all the way into the transmission pump.

Let me see?? Do you have a scat crank?

The thrust bearing and corresponding crank surface in my Mopar 406 crate motor got ruined because of this. I have put 3 bearings in it since then and will eventually have to replace the crankshaft.

Yes ! You need .100 to .125 "converter pull up".

It seems most of the time you will have too much, like .375, and in that case you can use washers or spacers on the converter pads to keep the snout of the converter engauged in the Transmission pump enough.

Anyhow, I did not find one source for an engine to trans spacer, but you definately need to put one in there. SO.......I ended up making my own out of .065 steel. Thats all I needed to get .125+ I purchased a "Mid plate" (motor mount)and used it as a template and used transfer punches along with pencil tracings from the back of the block to give me the final shape.

Thank you. It's an MP crank(maybe Scat?),the strange thing is I swapped only the block and the distance shrunk .1" plus. I can only think the blocks are slightly different. The engine mount studs are "off" about the same amount. I'll pick up some steel sheet and get busy. Thanks

The converter engagement deal would be more the .100" off. Think about it. The input shaft, stator, and pump gears certainly have more engagement then .100".

I highly doubt it's the crank if this combo worked before, you switched the block, and now it doesn't work...

Very strange.

Did you have the trans apart by any chance? I was wondering if the last clutch in the forward drum wasn't seated. That would make everything stack up by about +.100".

Just trying to figure out what could cause a +.100 shift (aside from the obvious block machining issue, but let's hope that's not it )

As I said,nothing has been changed but the block. Trans/converter never left the car,converter is fully seated in the trans. Prior to swapping the block it had 1/8"(.125"),after swapping the block less than .01". At this point it looks to me as though the block is the problem,but would love to find something that I missed. I'm not going to swap blocks,so I'll make a shim/spacer.

Update,I have been saved the time and aggrivation of making a shim by a mopars member who happened to have just what I need. Thanks to Laverne(SB412DUSTER)!