The large log heads are still easy enuf to find so its your choice if you want to spend the money on moding your old head or not.
Yes something is skewed but not like you think and that's why you can't really do a direct comparison of the older engines that are tested using the SAE specs for a Gross HP rating (as we're all engines 1971 and older), the newer engines which are tested as a Net HP rating. The differance was all in the way those older engines were tested, their Gross horse power rating was measured at the Flywheel. Back the. They also tested those the engines without any accessory's installed. I.E. That means no Alernator, Water Pump, Air Cleaner, Fan, etc. this could result in from 12 to 18 HP increase, plus they also had an open header type exhaust (no muffler) I don't remember what this added up to but maybe another 15 to 20 HP, it takes some horse power to turn all those accessory's. Though it wouldn't be a direct compareision check HP numbers of a 1965 to 1968 200 to a 1972 200 that would show you a somewhat close differance in the power ratings with and without the accessories and exhaust system parts.
After the Feds got involved in 1972 (and all the engines thereafter) they were required to be tested as they were installed in the vechical with all its factory equipment, accessory's installed, with the exhaust manifold plus a full factory exhaust, they were still measured at the flywheel yet now was for the Net HP rating.
Then when you start comparing either of those two HP ratings with what you would get when the engines run on a chassis Dyno (as in that above test) it's now running through the transmission, drive shaft, and rear axle (another 18 to 25 percent or more loss) that will add up to even less of a horse power reading. Sorry but an old stock Volkswagen wont put anywhere near 62 to 68 horsepower to the ground look up what kind of an ET they ran in the 1/4 mile in an old Road and Track, Motor Trend, Popular Mechanix magazine if any of them they ever tested them. As another example look at what the horsepower rating is on a 1982 Mustang 200 (3.3) six the same basic short block as the 1965 200 but with a much better beathing large log head installed, less compression ratio (not so good), with a better electronic Distributor, Coil, Carb, and more. Best of luck
it still won't even flow as well as a stock late model large log head (1977 to 1983 200 or 250 witch both are identical). But then if you also did all those upgrade mods your talking about to one of those later model large log head's you would see an addistional significant improvement in power. All this is covered very well in the Ford Falcon Performance Book if you have one if not you should get one. Best of luck
