Head swap

Discussion in '1974 - 1978 Mustang II Talk & Tech' started by jeffnoel, Jan 22, 2004.

  1. I've got a chance to pick up a set of rebuilt 351W heads cheap (casting #s D0OE-C). Which from the chart over at II.net will bump my CR from 8.4 to 9.1, I'm running a Edelbrock performer plus cam and 302 performer intake manifold, Hooker super comps with a Holley 600. If I get these heads ($200 for the pair) I am also planning on installing roller rockers in them. My motor has 41K original miles on it and I was wondering what kind of HP this combo might make.
    Thanks Jeff
  2. Hp ?

    Well unless you sink some money into a machine shop there not going to give a huge boost in HP. If I was you I'd have them put on a lathe type machine and make the CC smaller for higher compression. Have them port match the intake and polish and match chambers. Put some roller rockers and lifters on there with a nice set of springs to let yuh get the RPM's up there and you then should see a big boost in compression and HP. Plus its going to depend on how drastic of a cam you have. Other wise they won't be much to speak of as far as I'm concerned. But it all depends on what your looking for I guess. And how big your pocket book is. I'm guessing you won't get more than 300HP stock. Or if you do, probably not to much more.

  4. I agree with Tim. They are a very decent factory head. They respond well to porting. It is hard to tell what kind of HP you will make. But on my last motor I was running a fully ported set of D0's and it pushed my 68 mustang into the 10's. That was with a basic 351w, 40 over, big lunati solid lift cam, and tunnel ram w/2 450 holleys. The car was a full strreet car. I don't know the weight.
  5. If they were free, I'd say go for it. But for me personally I wouldn't fool with it for $200. The heads need bigger valves, porting, etc (especially on the exhaust side) and they don't have an ideal quench chamber for higher compression ratios unlike the newer head designs. To get good horsepower out of them you'd need to spend several hundred dollars and for that amount why not drop the dough on some aluminum heads or the Windsor Jr heads which I think retail somewhere around $800? Anyway that is my opinion for what it is worth.

  6. I kinda agree with CobraII351 and Dmoody. They are good factory heads and you can do the port work yourself which will make a huge difference.
    I guess i would have to base my opinion on how good of shape they are in.
    If you have to completely rebuild the heads then the price after purchase and machine shop labor and parts will quickly approach the price of a decent set of aftermarket heads which out of the box will flow better than the ported 70s. :shrug:

    I went this route on my 65 4vs and after all was said and done i got about $850 in them. They work great make great power but i have no doubt the aftermarket heads would flow even better.
  7. The heads are already rebuilt for $200, all I have to do is bolt them on. My II isn't a race car just something fun to drive on a nice weekend. And I'm not planning on a 300hp motor just more than the 140hp it's rated at.
  8. Then go for it. Those heads are a vast improvment over the stock heads. For $200 rebuilt they are well worth the money.
  9. definitely.....you will feel a nice difference over 4500 rpms with the bigger valves and the roller rockers.