289 heads on a '84 302 block?

[travis]

I know there was differences between the early and later 351w heads, but what about the 289/302's? Obviously the valve trains are different...I'm more concerned with cooling passages.

I've got a perfectly good relatively low mileage stock '84 302. It's got no compression (around 8.0-1) with 69cc heads. Can E7TE's be safely milled down to around 55cc...and live?

[mag2555]

I think those showed up on more trucks then any other motors that year.

The intake runners are said to be 124 CCs and sign off depending on the cam between 4000 to 4500.

There chambers where around 63 CCs and if I am not mistaken you would have to wack off .006” per CC.

With your needed 10 CC or so reduction I just don’t think it’s safe to mill .060” off those decks.

[BLSTIC]

Out of curiosity, what's the application?

E7TE take a bit of work to make good power so you're probably not going for high rpm performance.

[travis]

Just a mild cruiser with a little sound to it, nothing serious. It's a cast piston bottom end so don't need big rpm anyway.

I've got a couple sets of good E7's...I would port them of course. But I figure even with a .040" cut they might make 9.0-1 compression...and maybe that's enough. 54cc 289 heads would put it around 10-1

[289nate]

The beauty of some of the 289 heads is the small combustion chamber. At some point Ford changed the steam holes in the block and cylinder head. I have used modern cylinder heads on an early 289 block. Used modern head gasket and drilled the steam holes to line up with the modern heads. It’s very easy. I have not done it the other way around and I’m not sure it was changed by 1984. Just something to look into. Even if you don’t do it it’s not going to make it much if any difference.

[dfree383]

they bolt on fine, just make sure the water holes line up,

[jsgarage]

Are you or any of your friends competent to lay a few cast iron weld beads down in the chamber bowls? After contour-peening and maybe some cold-chisel work to kinda equalize the chambers, that would raise the compression without having to weaken the castings by deep milling. Since its just for a fun street machine, not a potential money-making class-cheater.

[Mummert]

C5 289 heads are better than "any" of the late 302 stuff, accept 68 302 4 barrel heads which are rare and pretty much the same thing. All of the GT-40 stuff has a 1.5 points less compression. That a tough pill to swallow on a small displacement engine. 289 intake bowls are bigger than 302 heads from 68-87, they have as cast short turn shape and the exhaust have no smog junk to fight with.

[n2omike]

289 has steam holes at 12 O-clock right above the cylinder. On 302's they moved them off to the side a bit. A head gasket can be used as a template to either drill the head or block so the steam holes between said block and head match up.

[blackford]

Looking at Bill Carrolls Ford V8 Performance Guide, he states that Ford does not recommend milling more than .050 off the 289 heads. Given the similarity between 289, 302 and E7 heads, the same could hold true for them also. When looking at some 5.0 Mustang forum posts, .040 seems to be the limit on E7 heads that folks are willing to go.