Waverous, for the intake manifolds, have a little patience and shop on corral.net. I got both the upper and lower gt-40s for $250. Those mustang guys are always upgrading. <br><br>If you are going to be running 24lb injectors, you will need for optimum performance 70mm throttle body and maf. (It's like putting a larger carb on - the 351 can handle it.) If you do this, then the ECUIV unit will have trouble keeping up with the larger set up. Check out the FFRP catalogue, they sell the computer with the larger maf and the 24lb. Another way to go if you have the EECU unit off the mustang, is to get an aftermarket chip which will adjust the comupter for the set up.<br><br>The gt-40 heads aren't sold anymore over the counter. You can find them aftermarket. If you go with the explorer heads, they are gt-40p which, as discussed under the gt-40p thread, require different exhaust manifolds. The gt-40 heads breath easier and give more hp than the stock. If you port and polish the stock, you should get approximately 40hp more from them.<br><br>All in all the sefi on the 351w is a great set up.<br><br>