If you can do the OPG, you'll find that installing the Whipple kit is MUCH easier! The manual could be clearer in some places but will get you by. I marked up mine with the intent of sending it to Whipple for review.
I did my OPG/TG myself and had no issues apart from getting the one pickup tube bolt started. I put the bolt in ahead of time and put an o-ring around it to keep it from falling out. Then I installed the pump. The o-ring stays there trapped in the hole through the pickup tube flange. It can't come out.
I took a GearWrench ratcheting combination wrench, heated the shank close to the head with a oxy/acetylene torch and bent the handle at an angle. Basically think of how a typical combination wrench looks on the closed end. My gear wrench now looks like that (and is not useful for loosening bolts anymore)
The flex head ratcheting wrenches didn't work for me because the head would fold rather than support the bolt. I guess I could have set the flex how I needed it and secure it that way with a weld bead or CA glue... Didn't think of it at the time.
