68 427/435 WP Pulley

[William Holder]

Hello I am confused about what water pump pully my car should have early January
1968 427/435 No A/C or PS I thought it is the three groove but I am seeing some people say two groove. Anyone know for sure and have Part numbers?
Thanks
Bill

[Joe L.]

Re: 68 427/435 WP Pulley

Bill-----

Early 1968 Corvettes with 427 may have used a different waterpump pulley set-up than later 68 427s. In this set-up there were 2 pullies "sandwiched" together forming what would appear to be a 3 groove pulley. The inner pulley was a 2 groove pulley of GM #3848904. It was 6-9/32" OD. This pulley drove the waterpump (captured belt) and alternator. The outer pulley was a 1 groove pulley of GM #3883235. This pulley was of 5-7/8" OD and drove the AIR pump. Incidentally, this same pulley combination was used on many 1968 small blocks.

Both of the above-referenced pullies are GM-discontinued, but are available in reproduction. The GM #3848904 is replaced by GM #3995641 which is still available from GM, but differs slightly in configuration from the original.

Later 1968 Corvettes with 427 and most 69-70 Corvettes with big block used a 3 groove pulley of GM #3889372. Some GM references say that this pulley was not used for L-71 427s, but that is incorrect; it WAS used for most 68-69 L-71 427s as well as most other 427s, except L-88/ZL-1 which used the same pulley set-up as early 1968.

I do not know when the changeover occurred in pulley set-up for 1968 427s.

[William Holder]

Re: 68 427/435 WP Pulley

Joe ,
Thanks !!
Also while I have you attention can you tell me what year a C3 headlight door part number 3938152 fits? I bought it as being 68 only but it does not appear to be any smaller than my others I have on hand?

[Joe L.]

Re: 68 427/435 WP Pulley

Bill-----

3938152 is not a part number for a complete headlight door assembly. However, I believe that it is a component of the right side, 1969-82 door assembly.

[William Holder]

Re: 68 427/435 WP Pulley

Im Sorry I was Not more clear. It is the housing assy that the lamps mount to, but my parts book says that it should be 3932935 for 68 and 3938115 for 68 to 80 second design so I don't see where my 3938151 fits in?
Any Idea?
Thanks again
Bill

[Joe L.]

Re: 68 427/435 WP Pulley

Bill----

I understood you. I assume that you are getting the 3938151 number off of the part, itself, and not off a GM box/parts label that the part is supplied in. The 3938151 is not a part number for the complete assembly. It is the part number for a COMPONENT of the assembly (which component, incidentally, was never serviced seperately). I think that it is a COMPONENT of the 3938115 ASSEMBLY. The 3938152 is a COMPONENT of the 3938116 right side assembly.

The part number for the complete assembly for these units is usually not found on the part, itself.

[William Holder]

Re: 68 427/435 WP Pulley

Thanks FOr the Help
Bill