I have a solution for your plug swapping headache... There is a seller on eBay that sells a machined socket that is shorter and has the end open, which you use together with a 3/4" Gearwrench..... I use this setup and have changed plugs on 3rd generation Camaros with Edelbrock TES headers and Flowtech headers and stock 4th generation LT1's in about half an hour.... you won't believe how simple it makes the job.
~Supercarvideos
Winchester, Va.