Here is a description of the red seals, which are like the FelPro style 2947 premium race seal. They are made for hi performance and vacuum applications.

Our “Premium Sportsman Series” rear crankshaft seals are engineered to provide confidence
in sealing a very demanding area of today’s advanced racing engines.
MATERIAL
Unique blend of premium Fluoroelastomer rubber with friction reducers provides minimal
parasitic losses and withstand intermittent temperatures up to 550˚F.
DESIGN
Special design sealing lip and parting surface area ensures confidence in sealing Dry Sump/
High Vacuum as well as Advanced Wet Sump applications.
RESULTS
Top engine builders in many forms of motor sports have realized the ease of use and sealing
benefits provided by these products.


The blue side seals were re-tooled for easier installation. Some people were having problems getting them to fit easily, so these have a minute tolerance change to aid in installation.

What I have found best, is make sure the seal retainer is dry, and use 3M 77 adhesive in the side seal grooves. The side seals are then " solid" witht he seal retainer. Hold the seal retainer at a slight angle outward, which will almost " hinge" in the blcok register. You can then stand the seal retainer straight up, then slide it down into position. I like to use a slight spray or coating of Dupont TriFlow on the seal retainer register of the block, and on the side seals themselves. Works like a charm. Make sure to read the instructions on properly aligning the rear main seal. You also DO NOT need to put ANY sealer on the seal ends where they meet! The seals are designed to NOT need that.