Originally Posted by Never_Evil
Yer honor, everything that guy said is bullshit!
I am going to repeat what 3/4 of the mustang sites will say. The GT40P heads are similar to the E7 heads except the bigger valves on the GT40P heads and shitty placed spark plug. You will need to purchase Specific headers for this head, if you go with factory or generic, you will not to get some plugs in or out and will not be able to get your plug wires on.
The 351w is about 1" taller than a 302 so to combat that, most guys use the convertible motor mounts. It will drop the engine about 1/2 to 3/4 of an inch. It is true you will need a new oil pan for the car, summit and jegs have them.
As far as going to 5 lug. You can either get GT spindles and 94/95 rotors or go with a Lincoln Mark VII setup. The rear conversion and be done with either a SN 95 axle, Mark VII axle, or using the driver side axle from two RBV (ranger based vehicles) explorers being your most plentiful and most useful. You can upgrade your carrier to posi and get a 31 spline axle vs the stock 28. The disc brake set up will also come from the Explorer.
Check out MidwestMustangAssociation.com, its a group based in WI, but we will get you the answers you need.
Good post. I went with the Lincoln front setup and it worked great. I'm sure your axle is an 7.5" anyway so you may as well go get an 8.8" axle and I'm pretty sure the Lincoln is a bolt in. I dont know for sure because I went with a 9".
One thing I didn't see mentioned is the addition of sub frame connecters. Definately do it. The unibodies on these cars will twist and crack easily.
Good to see some other Mustang people here.