C3 Big Block Rad Splash pans

[Tom Bishop]

Did the BB cars have a metal splash pan under the radiator? I have seen reference to them in the assembly manual with SB, but they seem to be absent in the BB. Can anyone confirm this please. Also were the SMOG pumps the same in SB & BB or different?
Thanx

[Joe L.]

Re: C3 Big Block Rad Splash pans

Tom-----

The "splash pan" that you described (actually called a "baffle") was used only with 68-72 small blocks with steel fan shrouds. ALL 1968-74 Corvettes with big block used plastic fan shrouds and NO baffle of the type that you described was used.

As far as smog pumps, for any given year the big block and small block smog pumps were generally the same. There was ONE exception. For 1969, Corvettes with L-88/ZL-1 used the 1968-style smog pump and not the 69-71 style pump that was used for all other 1969 Corvettes, big block or small block. It is also possible that some very early 1969 Corvettes, big block or small block, used the 1968 style pump.

The 1968 style pump can be used on 1969-71 Corvettes with no problem, at all. The 1969-71 Corvette pump should NOT be used on a 1968 Corvette (or, a 1969 L-88/ZL-1).

[Tom Bishop]

Re: C3 Big Block Rad Splash pans

Joe - How does one determine if they have the right Smog pump for the year? Is there a part number on the pump body and is there a date code?

[Joe L.]

Re: C3 Big Block Rad Splash pans

Tom------

There is usually no part number on the pump which represents the part number for the COMPLETE PUMP ASSEMBLY. There are casting numbers for the various components of the pump, but these are not necessarily unique to a particular finished pump part number. There is a date code on most pumps, though. It's stamped in very small characters on the "half-moon" shaped machine surface of one of the ribs of the aluminum pump housing. The pump model is also shown on the date code line as an alpha character.

Basically, there were 3 different pumps used for 68 to 78 Corvettes. The all 68 and 69 L-88/ZL-1 pump can be identified by the external relief valve seen on the pump's aluminum housing. The 69 to 71 pumps do not have the relief valve but do have a more-or-less flat area on the housing with a "roundish bump" in the center. The 72-78 pumps have a wider, flatter area on the housing which is similar to that used on the 1968 pump, except that there is no relief valve in the center of it.

[Tom Bishop]

Re: C3 Big Block Rad Splash pans

Thanks Joe - Once again a big help. Tom