I installed SW headers but found this write up to be very helpful
Jeal Header Install
I did not use the original bolts but went with stainless ... bought a complete set. If you are installing SW headers, study the bolt holes carefully ... you might want to "practice" putting a bolt into each hole. There's either 1 or 2 that you have to "angle" the bolt to get it started which I found impossible to do once I had the headers in place on the engine. i.e. I didn't get all bolts in which isn't absolutely necessary. Notice how many bolts were used in the OEM manifold ... the factory didn't use all the bolts that could have been used. Anyway, if you want to have a bolt in each hole, you will need to determine the tight fitting ones & probably get the bolt in place before you attach the header to the engine. This will probably take more than 2 hands which wasn't an option with me. I did the whole thing unassisted.
A lift would have made the job much easier ... again, not necessary, but I really wished for one.
The O2 connector on the right side is a B****. Impossible to reach the connector unless you are a 4 year old midget with small strong hands. I ended up snaking the connector from the engine harness out toward the front of the engine & adding an extension that was routed around everything back to the right side O2 sensor. Be sure to tie it up & insulate if necessary. The harness will MELT if it touches the header and it doesn't take very long to do this damage ... don't ask how I know.
Good luck ... you're going to love the end result. Headers really help the LT5 come alive.
George