They are a result of a collaboration between Pontiac and Air Flow Research - the premier cylinder head performance modification company of the day. These SD heads are' bare' and have virgin ports - NO porting or modification. They have also been magnafluxed with no issues discovered. Date codes are' J 18 2' and' K 18 2' indicating that the heads were cast in late 1972 for 1973 production, although the 1974 heads were identical. However, these heads will fit on ANY Pontiac 455+ engine with excellent results.
These particular heads were on an engine just once and run for a fairly short time - less than 15k miles - before being removed and stored for many years. There is some minor pitting in a few of the combustion chambers but nothing to be overly concerned about. This is shown in the pictures we've posted. Like to see detailed pictures of different areas?Please ask and we will be happy to get them for you. If you're a knowledgeable Pontiac enthusiast, you know how hard these heads are to find, especially when they're UN-MODIFIED , like these. We had an inquiry about the pushrod tubes shown in the intake ports. For those not that familiar with the SD455 engine, the pushrod tubes shown in some intake ports were done at the factory on ALL SD455 heads. Here's a detailed explanation, from an article in Hot Rod magazine. The round-port SD-455 cylinder heads were similar to those found on the R/A-IV and 455 H. Engines but with revised intake and exhaust ports for even greater flow. Pontiac engineers redesigned the intake port to maintain constant cross-sectional area, and the result was a noticeably wider and taller port just past the intake flange.
The pushrod bulge, normally 0.150 inch wide, was reduced so much that the pushrod passage in the head broke into the side wall of the intake port, and a 0.030-inch tube was pressed in to prevent leaks. Intake-port height increased so much the valve cover and rocker stud holes both broke into the port roof. When was the last time you saw a set of Super Duty 455 cylinder heads for sale?? It doesn't happen very often, so don't miss out because these won't last long.These heads are cross-posted in various venues and are listed locally at a reduced price. We reserve the right to end this listing at ANY time for ANY reason. We have many other Pontiac high-performance parts for sale, including an NOS #17054910 SD455 800cfm quadrajet, multiple 455HO and Ram Air IV intake manifolds, SD455 connecting rods, Ram Air V connecting rods, NOS Rochester quadrajets, an NOS 1112011 1970 Ram Air IV distributor and much, much more. What factory performance parts do YOU need for your Pontiac? The item "(pair) Pontiac SD455 cylinder heads RARE'J182' &'K182' dates exc cond BARE" is in sale since Wednesday, March 20, 2019. This item is in the category "eBay Motors\Parts & Accessories\Car & Truck Parts\Engines & Components\Cylinder Heads & Parts". The seller is "anakinvader94" and is located in Las Vegas, Nevada. This item can be shipped worldwide.