1 or 2 piece rear main seal with supercharged motor?

[fox3streetracer]

i am building currently a 410w with a 1974 351 block with 2-peice style seal.this engine is going to see roughly 10-12 psi boost from a vortech.was wondering if it would be worth machining the block for a 1 peice rear main seal,or if a double lipped 2-peice seal will seal as good as the 1 peice under boost?

 

[Rick 91GT]

The 2 pc rubber seal shouldn't be an issue, installed correctly I find they tend to leak a lot less then the 1 pc at times.

If your going to run a vacuum pump I would machine it for a 1 pc seal, and use a double lipped 1 pc.

 

[5spd GT]

Rick - Are the "double" lipped one piece different than a typical one piece rear main seal (one lip right?)

I am curious if a double lipped one piece would be good for someone wanting to change out their rear main seal.

 

[Rick 91GT]

Rick - Are the "double" lipped one piece different than a typical one piece rear main seal (one lip right?)

I am curious if a double lipped one piece would be good for someone wanting to change out their rear main seal.

Yes they are different....