Which heads are better?

ok, i have a stock 5.0HO in a wrecked 89 and I'm gonna put it in a 66 w/ a blown motor...I don't have any questions bout that, but since the engine was out and I have to swap intakes, oilpan, T/C cover, etc. I'm putting in all new gaskets and might do a head & cam swap...which leads me to my question:

Would it be better to use the E7TE heads and just open up the exhaust ports or
Should I use F3ZE "GT40" heads?

the car is an automatic and will live under 6000rpm also I will either get an E303 cam or comp cam...the upgrade to 1.7 rockers on the GT40's are a moot point for me since if I keep the F7's i'm switching to roller rockers anyhow.

So is the swap worth it? One source says "E7TE...are undoubtedly the best late-model castings." but then why are so many people swapping out E7's to GT40's?

the 66 had a crazy fire breathing 289 so the c4 is equipped w/ a converter that has a higher stall speed.......

I had a bad experiance w/ GT40P heads in ther past...just the plug sticking straight out, clearence w/ the shock towers and the needed different headers. but anyways i got the GT40's, not hard to locate a good set at all. I was seeking info on the forum about E7 vs. GT40 cause I was told on the street the E7's were good cause even w/ smaller valves they flowed good (w/ exhaust ports opened a little of course) and made great tourqe. The 40's I got are in better shape than my E7's and they were cheap so I don't have to spend time breaking down the E7's to port them.

I was told that w/ the E303 cam and some decent flowing heads that a HO would be good for 1hp per cube (@ the crank and it sounds like some here are doing just that) and the E303 is an economical easy to find cam...the 289 had a dual pattern cam and I think the cylinder pressure was too high because of it (I would have detonation on 92 octane)