Heads

i dont see gears in that list...get some 4.10s if ya dont have em yet. when you do H/C/I you usually lose some lowend power, so gears make up When you do heads its good to just do it all at once heads, cam, and intake. If you don't have gears yet though, do that first. 4.10 gears in your automatic car will make worlds of difference. Gives you the seat of the pants feeling. You'll love it

I agree, get gears first.

No, new heads, cam, and/or intake will not kill your engine if it is in proper working order. There are members on here with over 200K miles on their original shortblocks running H/C/I and blowers. The 302/5.0 is a really good bottom end. 115K miles isn't much at all. I have 146+K miles on mine, take it to redline all the time. I dont' even worry about it.

also, if you do get heads and you don't wanna go too radacal you can get some stock E7TE heads(the heads you have now) ported and rebuilt by "Thumper" and pick up some nice performance while still using the stock heads. Or you can get some GT-40 heads and get them ported. If you want gobbs of power most people will tell you to go with aluminum heads like AFR 165's. But you can get some good ol' iron heads to flow damn good.

sorry i double posted somehow

The first thing that "should" go out on you is your AOD if you get up there in power. Just try to drive it nicely... if that is possible. I just put a set of Trickflow Street Heat Heads, Trick flow #1 cam and Street Heat intake on my 130K engine. Too soon to tell what may go wrong but I changed out the Timing chain which was pretty loose and water pump while I was there as some preventative maintainance. Ford engines are really strong so you shouldn't worry about your stock lower end or the block. If you are worried pick up a main girdle support and you should be more than good. You don't have to change out your cam but while you are in the engine you should change out the timing chain and it isn't much harder to get to the cam from there. If this is a street car I would get the E303 just because it is carb legal(dunno if it is legal on an automatic tranny though) and should be fairly easy to dial in. The Trick flow sounds nice and lopey but it takes a bit to tune and the computer was pissed when I first started the car up. In my opinion, which probably differs from everybody elses, I think the Trick Flow Street Heat intake is probably one of the best. It is great for mid to high end torque without sacrificing your lower end which is just perfect for the street. From what I hear, don't quote me on it, the Holley is great for more high end horsepower but may sacrifice the lower end. Edelbrock and the gt40 intake are both good too. GT40 is a bit pricey but they all probably flow about the same. If you are going to go through with all of that work I suggest spending a couple hundred and getting a good tranny oil cooler and some lines. That can mean a world of a difference if your tranny survives. Good luck. Oh ya... gears too.
Kevin

Yes if you beef up your AOD and put a higher stall torque converter then you MUST get an aftermarket tranny oil cooler. If you don't you'll burn up your tranny quick. Heat is the AOD's worts enemy. 4.10 gears and torque converter and you'll feel a huge difference even with your stock motor.

I would go with the 3.73 gears. I did a head and intake swap and now I can't get traction with 4.10 gears. I can spin all the way through 1st and a bit of second before I really start moving if I just floor it. To help answer your question about the mileage concern I installed most of my upgrades after 140,000.