I currently have Lakewood's on my '72 (without adj. uppers). The stock uppers had poly-bushings on the frame side. Very stiff and not alot of suspension travel (the best 60' we could ever get with this combo was in the 1.90's and that was with a DOT tire).
I have gone in another direction (more of a handling/straight-line car) and spoke with Mark at SC&C (
http://www.scandc.com) as I had interest in going to the Currectrac's. He indicated that if I want to still do 'straight-line' to keep the Lakewood's and install the Currectrac's (adj. uppers). If I wanted to just go for a pure handling application (no drag racing) put back a set of rubber (or equivalent) bushings in the rear, and use the adj. uppers.
I am going to keep the Lakewood's and add the Currectrac adj. uppers (from SC&C). It will hopefully give me the best compromise between handling and straight-line.
Cheers,
Brian
'72 GTO.