[Preacher17]

The advice you're getting on heads is sound advice Ford heads are notoriously bad breathers on the exhaust side. But instead of porting your 289 heads if you can afford it step up to 351W heads. Bigger valves, bigger ports and its a bolt on swap you just need special bolts that you can get most anywhere. Still work the exhaust side a bit and you will have heads that breath freely and can handle more cam and intake.

 

[Preacher17]

your 289 heads should have 54.5cc combustion chambers with 1.67int/1.45ext valves. The 351W heads have 60.4cc chambers with 1.84/1.54 valves. This is an excelent bargain head for the 289. It has way more potential than the 289 heads and unless you're going to try porting them yourself, porting can be expensive. You should be able to do a gasket match yourself but think twice before going deeper than that unless you have a pair of junk heads to practice on first.

The chamber sizing is similar so compression should still be ok, and the bigger valves and ports will make all the difference in the world. As for how much power? That depends on a lot of things. To see good power gains you need to upgrade both intake and exhaust. A good dual plane intake and four barrel-stick with an autolight carb it doesn't get the respect it deserves and a good set of headers. Also think about upgrading the cam to a good street cam that will produce torque down in the rpm range where you drive.

If your on a budget this can all be done in steps as you have the cash but stepping up to the 351W heads will ensure that you are ready for all the other upgrades.

I'm currently building my own 289 using 351 heads. If fact I bought them about a month ago at a swap meet. I found a pair that had not been ported but did have screw in studs and guide plates. They set me back $300. There were two other sets I ran across that ran $200 and $250 that were stock and in good shape. If you do decide to get the 351 heads get heads prior to 1976 (check the casting dates) after 76 or so Ford made changes in the head that make them less desirable.

Hope this helps and good luck on the build.

Mike

 

[Preacher17]

By the time you buy a set of '69 351W heads, install hard exhaust seats, new valves, valve guides, stem seals, springs, retainers, keepers, convert to screw in studs and guide plates, you could have easily bought a set of World Products cast iron Windsor or Windsor Jr. heads with all that on them AND a much better chamber design AND better port flow.
For a little more $$ you could buy some aluminum heads from a number of manufacturers.

I think I need to disagree a bit here. Last time I checked, aftermarket heads ran more than a grand a set. You can get into a set of 351 heads with the valve job for half that. On a good street motor the 351 heads should be more than good enough. You need to have really stout camming before aftermarket heads are worth the money. If budget is no problem sure pop for the aftermarket heads, but for the money the 351 heads are a better buy.

 

[Preacher17]

I think your missing the point. Both questions were by folks building 289 engines. Both seemed to be on a budget. Eight hundred bucks plus whatever shipping runs for aftermarket heads is a bit unreasonable for a 289. Aftermarket heads are a nice luxury if you've got the dough but there are cheaper ways of getting there. The 351W heads are more than adequete for a 289...and most other small blocks. With a bit of work they will perform about as well as most aftermarket heads and not break the bank. If you're into "serious" performance you're not building a 289 anyway you have stepped up to a stroker or dropped in a big block. The 289 is a great street motor and will respone nicely to some common sense bolt ons the windsor heads being one of them. Headers, a small (600 cfm) four barrel, a dual plane intake manifold and a cam that makes torque down in the rpm range where you drive are the others. Do that and and you'll have a great motor for your 'stang and still have enough cash left over to do a few other things.

Mike

 

[Preacher17]

I don't really want to continue arguing this point but check out the head comparason under the forums tech tab it's pretty interesting you can make side by side comparisons of just about every head known to man for the sb ford...pretty cool, I didn't know it was there. Ported 351W heads stand up pretty well to the competion I was a bit surprised. There is an article there about porting your own heads too. Guess it really comes down to do you want to do it yourself or go aftermarket. I've always been a do it myself type I find it's a bit more fun. The building it yourself part is really what I enjoy most.

Mike