"Stealth" Pontiac Heads
In street racing, Pontiac people can usually determine what compression your running, or the potential flow of your heads, simply by looking at the head casting number. Running #16 d-port heads on a 455 is a dead giveaway that you have some serious compression as well as 2.11/1.77 valves. There is an easy solution to this. Simply grind off your head casting numbers with a Dremel Tool. When finished, take the forked end of a hammer, and tap some marks into the area you ground away to eliminate the smoothness of your grinding marks. When you paint over this area, it should look very similar to your end exhaust ports. Now no one will know what head castings you're running. Naturally, if you ever decide to sell the heads, you'll have a difficult time convincing someone what they are, so I don't recommend this to anyone that actually deals in Pontiac parts. This tip is meant strictly for those that see a "value" to this work (we're talking street racing here folks).
The technique I used on the "stealth intake" in order to put casting numbers onto the intake manifold can also be used here. An intake manifold doesn't get anywhere near as hot as an exhaust port, but rest assured that if you use JB Weld on an exhaust port, it will not melt off. However, if you have problems keeping paint on your exhaust ports, once the paint burns off you'll be left with the dark grey numerals of the JB Weld, so I don't recommend doing this if you have a serious paint flaking problem on your heads. Obviously, once you decide to use the JB Weld, the sky's the limit as far as casting numbers go. Why go to all this trouble? Personally, I was simply tired of people eyeballing my heads and then making judgements on my combo, so for years I ran casting #39 on my middle exhaust ports. Unfortunately, rumors then flew that I had experimental Pontiac heads, because no one could find casting #39 in any Pontiac book.
Street racing knows no morales, but if you think this is a bit too "stealthy" or deceiving, I'm sure more than one of us has been unceremoniously smoked by a nitrous-fed car that looked innocently stock. It's all part of the game.
As Big Daddy Don Garlits once said, "All's fair in love and drag racing."