I looked at that sender on the classic parts web site, it looks very similar the the aftermarket sender I used on my 50. My aftermarket sender was 1/8 pipe
So in my case I had to go from 1/8 pipe to 5/8 18 unf . That was the size in my 54 235 head for mechanical sender. (This is just an example for my 50)
The question is what size provision is in your 235 head? If its 1/2 pipe then try a 1/8 pipe to 1/2 pipe reducer bushing from the hardware store.
Take your sender with you.
Again, You'll need to verify what size your sender is.
Don't rely on my example
