need help building up some 351w heads for my 289

So you have $395.00 in the heads.....and then you need all the valves, springs, retainers, etc..... You will spend about $700.00.

Honestly, you are better off getting a set of Aluminum heads...for an extra 250-300.00.

Do as you wish, but I would look at the long term, and weight savings....Aluminum is the way to go.

Agreed....

$700 into a set of heads that are iron...and used. Not my cup of tea. I suggest you have them milled too so you dont lose gobs of compression from putting on a different head. Then you have to worry about piston to valve clearance and yada yada. You CAN pick up a set of used Aluminum heads that are ready to bolt on for under $800. Or even a set of GT40 heads that are iron, used, ready to bolt on...1.84/1.54 valves for under $400!

Shane

if you want RRs, you'll need to put in screwin studs and guideplates. More expense.

You could save back by porting them yourself. A basic cleanup and removal of the Thermactor bump is not Black Art, just takes patience and a good Dremel. There are many Net articles on how to do this, with full documentation.

For $200 you arent buying a "full race" porting job anyway, so you might as well save the money and learn something at the same time.

You didn't say what year head you got...
Assuming they are 69-74, you got some good heads there.
Port them yourself.
Mill them a little.
Machine for studs and plates.
Use 1.94-1.60 valves.

When you are done, you will have very good and streetable iron heads.
Good luck
Dave

Are they pre-1975 castings with 1.84" x 1.54" valves? If they're newer than that, then they're exactly the same as 302W heads, which have 1.78" x 1.46" valves and smaller ports. (except for the combustion chamber CC, of course, which is larger on the 351W head)

How about just freshening them up, using stock intake valves (1.84?) and a set of 1.6 exhaust valves. You'll need hardened exhaust seats installed, also, because the old heads were designed to run leaded fuel. Do some mild cleanup work to the exhaust ports and remove the humps. Keep it cheap and simple.
The machine shop can angle mill them(not too far, or the intake will need to be angle milled to match) and hopefully get the combustion chambers down to 55cc, which will give you 9.something compression with flattops.

You can make decent power with just exhaust work on those heads. I used to have a set of 1969s on my previous motor, and the car was pretty quick. Run them awhile, then sell them later and buy a good set of alum heads. Find someone with a mildly built small block truck, and they'll like those heads, because they can take a lot of abuse and provide nice low-end torque on a 351W.