Choosing the right 289 or 302 Heads?

[tom991]

I have a 65 Mustang 289 4V, D Code. Will all stock 302/5.0 Heads work with my 289 motor? Are there some years that are better than others. Or, should I stick with heads closer to 1965 and specific to that engine? I see some 302 heads on eBay with fresh complete valve jobs for less than the cost of getting a valve job on the heads on my engine.
I would like a little better performance but I pretty much want to keep the car looking stock, except for the 2 1/4" exhaust system that I put on it.


Thanks

[SVTcobra306]

Be wary of GT-40p heads off of Explorer 5.0 engines, they have a modified spark plug angle and can cause header fitment problems.

Standard Cast-Iron GT-40's off a 93-95 Cobra would work well, flow a little better than a K-code 289 Hi-Po head does. Should bolt right on, you will want flat top pistons to keep your compression at or a little above 9:1.

[tom991]

Originally Posted by SVTcobra306

Be wary of GT-40p heads off of Explorer 5.0 engines, they have a modified spark plug angle and can cause header fitment problems.

Standard Cast-Iron GT-40's off a 93-95 Cobra would work well, flow a little better than a K-code 289 Hi-Po head does. Should bolt right on, you will want flat top pistons to keep your compression at or a little above 9:1.

Thanks, So as long as they are GT-40s and not GT-40Ps they should be alright for use with headers. How about with a stock exhaust manifold. Would there be a fitment problem in that instance?

Tom

[SVTcobra306]

The P's would, again your plug wires will likely hit the manifolds. You should be able to find regular GT-40's cheap, the craze over P's has driven their price down.