Have plenty of band-aids and peroxide Seriously, if you can jack the engine a bit and pull the engine mounts it will go easier. Are you doing this on a lift or jackstands?
Do we need to loosen both engine mounts and raise the engine for both sides?
Yes & jack it from the center. Doesn't need to come up much to slide the mounts out. While you're at it you may want to consider replacing those squishy things anyway.
It will sound good but not worth it for HP. I still have scars when I did mine.
__________________
Mineral Grey 2005 GT, Ford Racing Handling Package, BBK X-Pipes, BBK shorty Headers Ceramic coated,Ford racing exhaust, CS67 20" wheels 255/35/20F 285/30/20R, SCT Prog., Lemans Stripes, Kenne Bell supercharger 10psi 490rwhp 480rwt,GT500 twin fuel pumps,Forged and Stroked block, 39lb injectors. More to come
This was covered in another post you will also need a very hot girl with small hands and a case of beer along with the above mentioned peroxide and bandages for her hands since you will be laying there drinking beer
__________________
1989 gt 5.0 5 speed Hurst short throw shifter, Brand new summit racing long tubes MAC shorty H pipe in to 2 super 50 series flows with 45 degree turn outs. MSD billet distributor MAC CAI 140 speedo all this and shes pretty on the way MSD 7 al ignition,
I had my local shop put on a set of JBA shorty headers. I noticed some HP gain, but nothing amazing. I was really disappointed with the sound. I was expecting a much deeper/throaty sound. It improved the sound at idle and at moderate / aggressive acceleration, but at WOT it is very loud and raw.
I am not unhappy with putting them on, but if I had it to do over I would of rather put the $750 toward the stage II Comp Cams which is my next mod.
After the CAI / Tune & Axel Back Exhaust you really don't have any other major WOW mods that are relatively inexpensive. Long Tube Headers which require a new mid pipe will cost north of $1K. Cams will easily run north of $1K, Forced Induction $5K+
Regarding your original post regarding installation: I like tooling around my car and I have a 67 Mustang I am restoring, but for my daily driver I personally feel $300 to have the installed by a pro is worth the money/time/pain I would of saved by doing it myself. Without the proper lift not a fun garage project, but I take my hat off to anyone who has the courage to take it on!
__________________
Jim - Beaverton, OR 2001 Ford Mustang GT Patriot Performance Stage II Heads, Comp Cams Stage II Cam, MAC Ceramic Long Tube Headers, MAC Pro Chamber, Magnaflow Dual Exhaust Catback, Accufab 75mm Throttle Body, Steeda Full Length Subframe Connectors, Eibach Pro Springs -2", 3.73 Gears, Steeda Tri-Ax Short Shifter, K&N Mustang FIPK Air Intake,SCT X3 Tuner, CDC Shaker Hood Scoop 01 Cobra Seats, 326 RWHP
but for my daily driver I personally feel $300 to have the installed by a pro...
$300?!?! Who? How? They wanted to charge me $700 to do my LT's, and it's the same procedure!!! The shorties are actually a bit more difficult because of the tubes getting in the way. Yeah, I'd definitely pay someone $300 to my headers again.
All Ford Performance $350 & Krazy Koncepts Performance $300
I paid $350 for the JBA shorty headers. For that money I couldn't justify doing it myself.
__________________
Jim - Beaverton, OR 2001 Ford Mustang GT Patriot Performance Stage II Heads, Comp Cams Stage II Cam, MAC Ceramic Long Tube Headers, MAC Pro Chamber, Magnaflow Dual Exhaust Catback, Accufab 75mm Throttle Body, Steeda Full Length Subframe Connectors, Eibach Pro Springs -2", 3.73 Gears, Steeda Tri-Ax Short Shifter, K&N Mustang FIPK Air Intake,SCT X3 Tuner, CDC Shaker Hood Scoop 01 Cobra Seats, 326 RWHP
Ford racing shorty header installation. 
Seriously, if you can jack the engine a bit and pull the engine mounts it will go easier. Are you doing this on a lift or jackstands?
Kenne Bell supercharger 10psi 490rwhp 480rwt,GT500 twin fuel pumps,Forged and Stroked block, 39lb injectors. More to come
