CYLINDER HEADS
There have been several cylinder heads used on the 262 since it began in ’85. Some of the changes appear to be minor, but most of them will create problems if the wrong head is used in the wrong place. Here’s an overview year by year:
1985-’86: The 1985 and ’86 engines used a 14079248 casting. It had two holes on one end and three on the other end.
1987-’91 TRUCK, EXCEPT HEAVY DUTY AND ’87-’93 CARS: These heads were the same as the earlier ones except that they had three bolt holes on both ends. The intake surface above the ports was quite narrow; it’s only about 0.250″ wide. The unmachined, cast ledge on the top edge of the head was 0.600″ wide. Look for c/n 14094768, 10144103, 14099067 or 12553050. All of these heads had adjustable rockers.
1992 TRUCK WITH TBI AND NO BALANCE SHAFT: These heads had a wider surface for the intake gasket even though they didn’t need it because all of the tooling was changed to accommodate the new heads for the VIN “W” CFI engines that were introduced in ’92. The 10144103 casting was carried over from ’91, but it had the wide intake with straight ports on the top. It can be used along with any of the earlier 14094768, 10144103, 14099067 or 12553050 castings from ’87 through ’91.
1992-’93 TRUCK WITH CFI, BALANCE SHAFT: When the high output VIN “W” engine with central fuel injection was introduced in ’92, the heads were redesigned for the application. They had “eyebrows” added to the top of the intake ports to make room for the injector nozzles, so the intake surface above the ports was increased by 0.250˝ for improved sealing, and the cast ledge above it was narrowed down to 0.350˝ to provide more room for the intake manifold.
The 10077626, 14099064, 10240209 or 10238181 castings were used, but be sure to check them over carefully because there are two versions of the 10238181 and 10240209 castings with an important difference. In ’92 and ’93, they came with an 8° top angle on the intake seat and a 75° throat, but that was changed to a 30° top angle with an 80° throat in ’94. Separate the 8° heads from the 30° heads and use them only on the ’92 and ’93 engines.
Tonawanda switched to “net lash” rockers in ’92, so some of these are adjustable and some aren’t.
1993 TRUCK WITH TBI, EXCEPT HEAVY DUTY: The intake manifold on the TBI motor was modified in ’93 to take advantage of the wider intake surface that was machined on the ’92 and up heads, so these engines must have the heads with the wide intake and should use the castings with the 8° top angle on the intake seat.
1994-’95 TRUCK WITH TBI OR CFI, EXCEPT HEAVY DUTY: The top angle for the intake seat was changed from 8° to 30° and the throat was opened up from 75° to 80° to give a 10% increase in intake airflow for better performance in ’94. The same heads were used on both the TBI and CFI engines through ’95.
Both the 10238181 and 10240209 castings were used, but they have to be visually sorted because the early ones with the 8° seat probably shouldn’t be used on the ’94s and ’95s. If you do decide to stretch the rules and use the ’93 heads on a ’94-’95 engine, be sure to use them in pairs. Some of the ’94s still had adjustable rockers because Romulus didn’t switch over to “net lash” until ’95.
1996-’98 ALL TRUCKS EXCEPT HEAVY DUTY: There was another all new head introduced in ’96. It had bigger intake and exhaust ports, no exhaust crossover and four angled bolts for the intake. It’s the 10235772 casting that was used up through ’98.
1989-’95 HEAVY DUTY TRUCK WITH TBI: There have been three different heads used on the heavy duty 262 since ’89.
1) 1989-’92: The original head, c/n 14099066 was used up through ’91. The 10144115 casting with the wider intake surface showed up in ’92 even though the narrow one still worked. Both of these castings are interchangeable.
2) 1993: The 14099070 casting came with an 8° top angle on the intake seat in ’93, but it was also available with the 30° top angle in ’94 and ’95. Sort them accordingly and use them in pairs.
3) 1994-’95: The 14099070 casting with the 30° top angle for better airflow should be used on the ’94 and ’95 engines. Be sure to use them in pairs. See photo.
All of these heavy duty heads had hard donut seats, replaceable guides and heavy duty exhaust valves with 3/8″ stems.
1991-’93 SYCLONE AND TYPHOON WITH TURBOCHARGER: The turbo motors used the same heads that were installed on the VIN “Z” throttle body motors. It appears that they came with the narrow intake surface all the way through ’93. Look for the 14094768, 10144103 and 1409967 castings.
KNOCK SENSORS
Beginning in ’86, some of the 262s had fuel injection, and by ’87 all of them were fuel injected and computer controlled, so they had either one or two knock sensors. It’s almost impossible to know whether the engine came with one or two and where they were located, because it varied by year, model, engine and application.
The sensor has been installed in the top or bottom hole in the left head, in the bottom hole in the right head, in the back of the block or in the back of the right head. The wiring harness will not reach if the sensor is in the wrong location and that the sensors can’t always be interchanged because some of them have tapered pipe threads and others have metric threads.
So, it comes down to practicing damage control by building all of these engines with a fail-safe combination like this:
•Drill and tap every block for a metric knock sensor.
•1987-’92: The left head must have two holes with at least one wet hole on the bottom. The right head must have at least one wet hole in the bottom location.
•1993-’95: The left head must have two wet holes. The right head must have at lest one wet hole in the bottom location.
You may have to drill some that came with a dry hole on the top and convert others by drilling and tapping a second hole in order to have enough heads. Check to see if the casting is thick enough before drilling it. Some of them like the 10077626 don’t have the pad so they can’t be converted, but others like the 14099064 can be drilled even if the second hole isn’t there. It may take some extra time, but using one of these combinations will avoid all kinds of problems in the field.