Chevy heads

[schiada96]

What is the difference between a 990 head and a 188?

[elimination]

I think what you mean is the 088 and 990? The 088 is the replacement head for the 990 head used on Gen v engines. The difference is that when used on a Gen. IV block, most need the blocked drilled to allow coolant to circulate through the head properly to eliminate hot spots. But I do believe that the 088 head can be used on a Gen IV block without any mods. if being used on a marine motor....
Hope that helps

[Squeezing Spectra]

Schiada96 absolutely nothing but the number 188 is the last revision of the 990 head it was the last number that GM repalced the 990 with it was avaliable till about 1994 but they are identical heads, the 088 that he is talking about is a completely different head it was not produced till 1993 when the gen 5 big blocks were realesed it is a lightweight head with bolt down rockers non adjustable and has larger water ports to match the late model gen 5&6 blocks and it is not interchangable with an early block you will have a major water leak into the valley area. Bruce
[ May 01, 2003, 12:55 AM: Message edited by: Squeezing Spectra ]

[schiada96]

Thanks for the info

[elimination]

My bad for not knowing about the 188 but I know that the 088 can be used on a Gen.IV block without problem if the correct gaskets are used (Fel Pro makes them). Eliminates the problem that was previously mentioned. argue