Thats BS on the TTA check valve. It's the same one used on every Camarobird. It's also the same one used on NA G-body.
The only difference I've seen on check valves is the size of vacuum hose used. The stock size is 3/8 and most of the newer vehicles use 1/2". IIRC the nipple on the stock TTA vacuum block is 1/2. I've been using the stock plastic vacuum block for a long time with the 3/8 hose swedged on.
GM Part Numbers
3/8 check valve 18021981
1/2 check valve 18022219
You know it's kind of a moot point when this type of discussion comes up. There are very little parts to rebuild the PM and a reman'd unit is expensive. Both have their merits and they also have their faults. IMO the PM is the only way to go if you drive your car at 110%. And who does that? Go with the vacuum if your car is a DD or sees limited track time. There are ways to drive a TR fast with vacuum brakes. It just takes time to learn how. About 11-12 seconds for most of us.
Crank your boost up 25lbs.Run to 100mph Then jam your brakes on in a quick emergency stop. I like you so make sure you have alot of stopping room or your foot is near an emergency brake :biggrin: