I can get a set of Iron World products indsor Sr. heads for my 351W for a decent price. But im debating if theyre too much for my combo which is pretty much a stock 351w. Ill add a cam at the same time, but it will be mild, 210-220 duration and probably under .500" lift. I know the heads and cam will really waken the motor up, but i dont need anything wild in my EB, but more power would be nice. I was thinking about GT40 heads, but all the sets that are in decent shape i can find are the same price as these World Products. Think these heads are way to much?

you didnt mention a price

you can never go wrong with big heads IMO
those are a street head

The guy wants $400 for them, theyre complete.

I'd jump on them. On a 351, the port and valve size won't be as much of a factor as say on a 302 like I'm running my Aluminum Windsor Sr.s on. You'll have a great set of street heads with plenty of room for more power when you decide you want it.

Thats a good deal, Those are good heads, make sure you spec the valve springs with the cam you want to run, with aftermarket heads, its anybodys guess what cam those springs were intended for. Too much spring and wear out your cam, too little and valve float city. Cheap insurance to just get new springs/locks/retainers.

Not too much, Go for 'em! You will notice a large improvement over the restrictive stock heads. I run them.