Couple of Novice questions on th400 rebuilding

I have a 65 st400 I want to rebuild myself. not going to be high hp as it's just a healthy nailhead engine with a little extra oomph. I have heard and read that the early cases lacked adequate support and a case saver is recommended. is this an issue with a less than 500 hp low rpm scenario. also since I have the early trans I should have a 16 element intermediate sprag. is there any need for the 34 element sprag in this situation? I do intend to go with a later valve body and a trans go shift improver. I have a brand new 67 st400 with all the good stuff done and I could easily swap all the internals over to my spare nailhead case but I really dont want to cannibalize that trans.

 

The stationary center support has its teeth dropped in directly against the
case. That was found to be a wear spot, so the teeth were made .040 inch
thinner and a .040 thick ring was put in first for the teeth to rest against,
starting about mid 69. If you can find the parts they will interchange, or
cut yours .040 and get the ring.

I always convert to the later pan and filter (easy to find), along with a drain
in the back of the pan. Some say the Buick early valve body/plate was not
as responsive, but a 68 up valve body/plate may be bolted on. It has the
5/16 NC hole to hold the filter, or tap your own in the original.

You can convert to the extra disc (6) direct clutch by using the extra thin
piston, I have purchased it on Evil Bay. But last time I just took a 70 Cad
trans with all the above (except drain) and just transferred my switch pitch
parts over to it. good luck, Bruce Roe

 

Do you have a picture or part number for this ring? I'm trying to find one and I can't seem to find it in the parts breakdown or my Doug Roe book

 

The first link shows several rings going into the trans. Note the case teeth, little columns
of aluminum around the outside. The teeth of the center support (in another pic) slide
down into the case between them till the outer teeth end in a solid ridge. At that level is
the farthest in ring, which the teeth rest on. In an older trans with no ring, you will be
able to see how the teeth are starting to work their way into the case.

Never saw that case saver piece before, maybe for turbo engines.

There have been so many TH400s around (useful for parts), that I have walked away
from some seen left on the ground at car meet places. Maybe now harder to find, I
have no shortage here but not enough to market. Bruce Roe

 

That aluminum case saver piece is for trans-brake cars and you have to eliminate the band to install it so there is no engine braking. I have no desire for that feature