Will bolting on a set of 69-74 351 Windsor heads improve power and torque? What needs to be done in order to make the 351 heads properly fit? Are the 351 heads better vs. the stock E7TE's that i currently have? I currently run a 88 LX with h-pipe, dual exhaust, and a cold air intake with pulleys, TB is on the way...

351W heads will give you a larger intake & exhaust valve, larger port volume and no emissions "humps" in the exhaust ports. This in turn will give you more power. However, they will not have hardened valve seats and will have larger spark plugs that make it more difficult to change them when you have long tube headers.
The hardened valve seats can be fixed at a rebuild shop, and will allow you to use unleaded fuel.
You will get the most power if you add other parts as well. The 351 heads will complement a new cam & intake combo more than it will the stock setup.

Will the 351W heads cause any valve-to-piston clearance problems?

No. unless you have a large lift cam. Then you should check no matter what head you use.

If you are looking for the 351 heads that have the 1.84 intake and 1.54 exhaust then you need to find the early pre-1975 heads after 1975 the 351 heads are the same as 302 or it was 1977

You will need different head bolts. The 351 has 1/2 bolts and the 5.0 has 7/16. ARP makes a bolt that has a larger washer area to work with the larger holes (Ford Motorsports too)

Tony B.

I installed 69 or 70 model Windsor heads on my 93 GT along with a Comp 280 Cam, 24lb. inj. 73mm, 65TB, Cobra intake and 1 5\8 shorttie Mac's and h-pipe and Filter charger all at the same time. I'm very happy with the performance and it sounds killer. I had to get special head bolts and push rods. plug changing is not bad with rite tools.Car also has 3.73's & pulleys. Oh! and I did have to get some 1.6 roller rockers.

If you're going to buy different heads, you might be interested in this
www.geocities.com/MotorCi...t40p.html