Hell, Im just about to finish my 455 w/200 4r into my 70 cutlass. My issue is when bolting up the torque converter, it doesnt sit flat. its resting on the flexplate balance weight. this leaves a gap under all 3 holes. Should I use washers between the flexplate and torque converter? Is my flexplate on upside down. I had the engine completely balanced and the flexplate had the bolt marks on the weight side and the engine side had no marks, so I installed it that way. I had this same issue on the last engine before this rebuild. the left felxplate is from the rebuilt engine and the right is from the 403 removed from the car, Thanks

 

Chevy converter? I had the same problem. Yes, you can shim it with washers ONLY if you have enough endplay to keep about 3/16" gap between them before bolting it together. I did not. If it is to tight, you will trash your trans pump or tweek the flexplate as I did. I ended up just changing over to a BPO converter that has the feet welded on to clear the weight. However mine is a turbo 400. Hope this helps.

 

Yep, it does have about 3/16 between the flexplate and converter but about 1/8 to the flexplate weight.

 

After adding washers or shims, it should still have 1/8" minimum. Once I added these, I had zero clearance the first time and tweeked my flexplate. I had to replace it and the converter. At least the trans pump survived. I only ran it for about 1 minute and noticed the flexplate wobbeling bad. After removing it, it was bent.