Drilling the drain back hole out to 5/16 of an inch is to prevent fluid pressure building up between the seal and the pump and shoving the seal out. Apparently its an issue, especially when they get a few miles on them and the pump bushing isn't what it used to be. The other mod, I believe it was to the TCC circuit I'm assuming puts direct line pressure to it or something along those lines. TC lockup even with a stock converter feels like a firm up shift. Those holes are kind of hard to drill going sideways into cast iron though.

 

I may give it a shot this weekend

 

I drilled mine
just take your time and MAKE SURE you drill it STRAIT..lol No biggy

 

I did not have that page in my instructions but wish I would have had it during my recent build so I could have done the pump mods. Oh well....

Only for about 3000 miles till my converter clutch came apart and clogged up the system. I recently R&R'ed the tranny and installed the direct springs and thicker intermediate snap ring then.

 

are you refering to the hole through the pump ir the partition? Im am just not sure how I could drill the partition straight when you have to go at an angle?

 

the hole to relieve the front seal. You are right, no way to drill the other one strait..

 

cool I let you know if I need a new pump or not after the weekend

 

was the paper gasket the only gasket you needed?