will the cylinder heads off a 86 5.0ho work on a 68 block, and with a Eddy performer rpm intake? and should i excpect any performance increase or not,
i would be doing this as a repair rather than an upgrade, the performance isnt really a big deal
86 heads are junk your better off going with a set of e7te's you should be able to find some on ebay for $50 plus shipping. I know that your just doing this as a repair but I dont have a full answer to your question so I am only stating my opinion.
It's not just a bolt on, you're going from stud mount to pedestal mount rockers. Not sure what pushrods will be the right length, you'll probably need to measure. You'll have to plug the air pump holes in the heads too. You might lose HP, depending on whats done to the car and what heads you have... you might lose some compression.