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Bolted up my newly rebuilt tubro hydramatic 350 this evening to my '95 350 engine. (both out of truck) It went together fairly easy and I snugged up the bolts. Started to put in the 3 bolts joining the flex plate to the torque converter. Uh-Oh! Torque converter was tight against the flex plate. Hmm.. this aint right,,, The notched drive tube had slipped out and rotated, or I didn't get it seated right in the first place. Separated engine and tranny, rotated converter till the slots dropped in, and re-installed. Now the converter has about 1/4 inch free play fore and aft as I expected, and let me bolt converter to flex plate. So. I hope I didn't do any damage. Did I?

Maybe- - - -but if you didn't run the engine, probably not. I've seen the drive lugs get broken off the internal gear of the transmission pump that way, but it usually doesn't happen unless somebody spins the starter with the drive lugs jammed.
Jerry

Hy redwing, it happens to the best of us once in a while, one trick an old transmission man taught me years ago was to shim between the fly wheel and converter, there must be some clearance but keep it as close as you can. I have always done this since, sometimes three washers will fit in there and still have some clearance, the only other consideration is that your bolt still has adequate thread engagement, (might have to use a longer than stock bolt), that way you get maximum pump drive lug contact, hope that helps.

My only concern was what might be able to be pushed backward in the pump assembly by the drive sleeve since I don't know how the pump is designed. However, the transmission case to engine block snugged up with very little resistance, the flex plate showed no deflection, and backing off the case bolts less than a quarter inch freed the converter to turn. So.... Like Will Rogers said --- Worrying is like making payments on a debt that may never come due. LOL

The two square slots in the converter hub engage corresponding studs on the inside diameter of a gear-type pump at the front of the transmission. Those lugs are pretty beefy, but I have seen them sheared off at times, resulting in no pump pressure, and sometimes some scoring damage to the pump housing from the broken-off debris. I always fabricate a small flat metal tab that bolts to the transmission case to hold the converter back snug into the pump while I'm installing the transmission, then remove it when it's time to bolt the converter to the flex plate. The tip about shimming the converter/flex plate junction is a good one, as long as you don't overdo it. A little fore/aft movement is necessary.
Jerry

I have seen pumps break shortly after a "mechanic" installed a G.M. reman wanting warranty. If the converter insn't properly indexed to the pump you can crack the rotor and may not know it until it fails. Kind of how lucky you are feeling.