"...Wondering why nobody says... Wow great idea. Get some old high comp small valve heads for practically nothing cause nobody wants them, spend $750 at the machine shop, throw them on and rip it up? My experience is that if nobody says that there is a very good reason. What reason?

I would think that any second hand 40 year old heads are going to make a trip to the machine shop anyway so pressed in studs could be easily resolved..."

(1) I wouldn't say "nobody wants 'em", since there are lots of guys who have used the #17 & #47 heads, on performance builds.

(2) I'm not sure that you can get ALL the GOOD QUALITY parts & machine work necessary for a high performance head job, for $750. I'm guessing $200 for the ARP conversion studs + labor for proper installation. The holes must be tapped correctly. Then the bottom of the studs must be ground down and properly finished, since it is said that they are too long, as produced. Machine shops don't give away free labor.

Then, if you plan to do a lot of driving, most say you need to have hardened valve seats installed, for use with unleaded gas.(Many say the seats are not needed.)

Most say it's better to buy one piece stainless valves, which add to the price. Some say it's just fine to use the old factory 2-piece valves, if you're gonna use a small cam and stock strength valve springs.

Most say it's best to use the good valve stem seals, which fit around the valve guides. The guides must be machined for these seals, in most cases. Then they'll charge for for doing a "multi-angle valve job".

There are additional charges for cleaning, and any surface machining done. If you have much cut off the chamber side, to increase compression, they need to cut an equal amount off the intake port side, in order to maintain proper intake manifold fit.

If you can buy some GOOD cores for $200, add that to the cost.

And that does not include any type of porting or gasket matching you may want done. So, MANY have spent MORE than $1000, when transforming these low performance heads into high performance heads.

(3) If you really search for 'em, you can sometimes find some good heads that somebody else has already spent the $$$$ on, and save a few hundred bucks. You can usually find most anything you want over on the PY site. There are usually some guys switching over to alum heads, who have their iron heads up for sale, to help pay for the alum heads.

(4) BUT, if you wanna start from scratch, with the old small valve press-in stud heads, and have 'em built correctly, AND have the $$$$ to pay for it, then by all means, DO IT ! That way you'll know exactly what you have, and won't be using somebody else's old used stuff, that they didn't want any more.

I suppose what I'm trying to say is that you have options. But, the decision is all yours, as to exactly which way to go with your build.