Horse

I am rebuilding a Turbo II and I plan on replacing the stock Turbo with a Turbonetics T-66 turbo, don't worry I am upgrading everything to handle the turbo. Here's the thing I'm not sure about all the options, I know I want the T-66 and I want the Ceramic Ball Bearing (and I know they are hard to repare), but what about the other stuff like O or P trim, on center or tangential, and what A/R ie. .58, .69, .70, .81 or .96. I'm not sure what it all means and which is the best for me and the car will some one help explain. Here is the link to a page that tries to attempt but I still don't get it, http://www.turboneticsinc.com/guidelines.html
Thanks guys

Horse

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