68 289 heads

October 03, 2005, 08:14:01 PM

i have a set of 289 heads off a 68 cougar. would these be a better set of heads than the 87 so heads? would i be better off with a set of e-7s?

Re: 68 289 heads

Reply #1 – October 03, 2005, 09:27:29 PM

Those heads do not have hardened valve seats and the valves will likely burn in 5-10,000 miles, also they use stud type mounting for the rockers. They have smaller combustion chambers that will raise compression approx one point. Performance wise they are a little better than the E7 because of the added compression, but you'd likely be better off with the E7s..

68 289 heads

Reply #2 – October 09, 2005, 10:12:16 PM

If those heads are actual C8AE (or similar year) heads, they are actually 302 heads, as the 289 went bye bye for 1968, replaced by the 302. What you also have to look for is whether or not they are 4 barrel heads (there is a 4V cast into the top of the head, in between two rocker studs). Why? Because the 2V heads have 58 cc chambers, and the 4V heads have 53.5 CC chambers(ports are the same, I have a set of both heads), which equals either a 1/2 point or full point of compression increase, depending on which heads they are.

You really need to redo these heads before installing them, by upgrading them to hardened exhaust valve seats, and machine the intake valve guides for teflon seals, as the exhaust side guides don't need it. You might also add screw-in studs if you are adding a larger cam, as those old heads occasionally work the press in studs out, but you have to retain the rail-type rockers if you do, or add guideplates and non-rail rockers. If you can run good gas, they add some snap to a later 302...

68 289 heads

Reply #3 – October 21, 2005, 09:45:19 PM

Have these heads redone with some screwin studs and they will be better than the e7s, better compression. 66' 289 heads would be better.