"My friends say heads are my best bang for the buck over intake"
This, to me, implies that he wants to make as much power as he can with as little money as he can. Heads are a huge step toward wanting to make big power. It would be nice if he got back to us and commented a little more on what he is really after. There are some assumptions that he made that are incorrect. e.g. That he should keep his stock cam for driveability reasons. The cam is the heart of the engine. If you don't have a good heart, nothing else matters.
For the same cost as the heads (Good set is about $1200), he could get an intake ( $395 for TFS ), a 65mm TB ($175), EGR plate ($55 He could skip this since emissions is not an issue), and a 73mm MAF meter ($125). $750 so far. That leaves him an additional $450 for 2 1/2" off-road H-Pipe ($159) or X-pipe ($200) and a cat-back for about ($250).
At this point he would have taken care of all the exhaust and intake stuff. He should probably hold off on installing the exhaust until he gets the new heads. Next year, he could get the heads ($1200), cam ($150-$200), 1.6 RRs ($240), pushrods ($100), hydraulic roller lifters ($110), and studs ($25). Then he's all set with an additional $1825-$1875. Let's make it an even $2000 since he'll probably need a FPR to boost his pressure some.
It'll probably cost him a total of about $3500 (There's stuff like gaskets and fluids that runs it up another $300) to have a pretty powerful, driveable engine.
Since doing the heads without doing the cam and the other related stuff is a waste of time, I suggested he do the intake first. This doesn't involve having to remove accesseries. It's also good practice for the much bigger job of doing the heads. We all know that it's at least twice as easy to do the second time around.
If indeed, he doesn't really want to make big power, he may just want to get his stock heads ported and his intake extrude honed and then add the 1.7 rrs.
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351W 89 Mustang GT Convertible