I have a late 904 lock up trans that I am using a non lock up valve body and non lu converter and this gap is bothering me. Thanks in advance for advice.

The VB will not sit down flush all the way seated? If so can you see where the interference is?

Did you change out the lock-up parts up front? Converter splines are different. Not sure about pump & other internals there.

Yes, I swapped out the lock up parts for non lock up parts. The concern is the small exposed gap the VB does not cover in the 1st pic above the front servo piston. Not sure if this is an issue or not? The valve body is from a non lock up trans as well.

something is preventing the VB from seating flush. remove it, then use a straight edge to find out what it is, then report back.

if there is no passage in the vb or the case in that area it shouldnt be a prob as long as the gasket seals where it should

The VB sits flush,thats not a problem. Thanks

Never seen a gasket in this location. Thanks

sorry that is correct(brain fert) but my passage comment still has me wondering.i wish i had a 999 here i could look at.

FWIW, when the lockup transmissions were introduced in '78, the factory said the case was backward compatible with earlier years (probably back to '71).

as the pic is a little blurry, and my old eyeballs are as well, it looked [to me anyway] the VB was not sitting flush, so i thought that was the gap you were talking about.
my fault. sorry. continue on.

I should have circled the problem with a marker but think I've found the answer. Thanks

So, what was the answer?

Not an issue. I'll know soon enough.