To start off, I have a regular cab shortbed 6.0 2003 GMC Sierra. It's got a TBS, cold air intake, and a borla pro xs. It's a quick truck, but I want it to be quicker. I bought Longtube headers and they should be in any day now. The past few days I've been looking heavily into a cam and heads. Just based on what I've read and saw Texas Speed was the way to go. I gave them a call and they've really got me set up with what I need. I'll be getting a 224r 114 LSA cam from them along with new valve springs, rods, lifters, timing chain, oil pump, and just a few bolts and parts to put it back together. I've also decided to go with new injectors. Now when I called the guy recommended me to go to eBay and look for 8.1 Marine injectors so I've found both 42lb and 60lb sets and I'm a little stuck on which ones to get as there's only a $20 price difference. I want to make sure I get everything lined out before I get into all of it, but I can always replace the injectors another time. The only thing I'm worried about is would I be able to run stock fuel lines with the 60? I know I could the 42 as I've seen many do it. Also I'm not as to whether I'm going to replace the lifters or not yet. How do I pressurize the block so that the valves don't fall in while I do this if I plan to leave the heads on? Any suggestions and advice is appreciated