Cylinder Head

When ordering a GM 2.5L head you will find that the casting nuber is the same on many differentheads. The location of the boolt holes are different, as see Cast Iron GM R&U n above, the length of the valves and the size of the valve stems ate different even on the same casting. You and your customer must check and make sure you have ordered the correct head before installing it on the car.

GM 2.5L cast Iron Head

GM 2.5L Cast Iron
2.5L R-373 call for availabilty	1982-83	HAC 2.5-373R	295
2.5L R&U-496-10101496	1990	HAG 2.5-496	295
2.5L R&U-485-10044485	1990	HAG 2.5-485	295
2.5L R-552 call for availabilty	1982-83	HCG 2.5-552R	295
2.5L R&U-655-10044655 8mm valve	1987-1988	HAG 2.5-655	295
2.5L R&U-514	1990	HAG 2.5-514	295
2.5L R&U-10044642	1990-	HAG 2.5-642	295
2.5L R&U (702) Wide call for availabilty	1982	HAG 2.5-702	295
2.5L R&U767 11/32 valve	1986-1987	HAG 2.5-767	295
2.5L R&U-10038806	1990	HAG 2.5-806	295
2.5L R&U-808 Shot vale 8mm	1987-1988	HAG 2.5-808	295
2.5L R&U 10038808 11/32 valve	1990-	HAG 2.5-808	295

Note on rear wheel drive cars the core pluge are located on the other end and must be swapped.

3.8L V6 Buick 182391402, 2136, 2261, 4781 HCG 3.8 265.00

call for availability of casting #

One are Two

Casting Number

casting number not listed

4.3L Chevrolet call for availability of casting # HAG 4.3 265.00

Casting # 245, 248, 268, 683, & 769 Early

Casting # 103, 890, 772, 181, 209, 256, 742, 113, & 064 Late

Casting # 53480, 55865, 051174, 1174, 88640, & 88840 Roller cam turbo

Note sum of the later modle have injection ports in head and the casting is the same number as those that do not.

Port Injection

Casting Early

Casting Number Late

Casting # Rollar Turbo

Your Casting Number not Listed