Many folks think that external oil baffles (i.e. baffles that mount to the main studs rather than those welded into the pan assembly) were only used for 6 quart system oil pans. However, that's not the way it was. There were actually 4 different external baffles used for small block Corvettes over the years.
GM #3769768. The first was a "flat" baffle plate used for some 1960-61 applications. This baffle was also used for 1963-65 Corvettes with 6 quart oil system as well as some early 1970 LT-1 and all 1970-72 ZR-1. It is pictured in the first photo below. It is designed to work with certain 1960-61 oil pans as well as the 63-65 GM #3820001 and the 1970-72 GM #3956670. This baffle was GM-discontinued in October, 1995.
GM #3989075. This is one that few folks know about. It was a "shorty" curved baffle plate. It was used for 1970-72 LT-1 with 5 quart systems and all 1973-74 L-82. It is designed to work with the GM #3820000 oil pan. It can be seen in the second photo below. This baffle was GM-discontinued in October, 1982 and can be difficult to find.
GM #3927136. This is the "long" curved baffle. It was first used for 1968 Z-28 Camaros, having replaced an earlier baffle used for 1967 Z-28 Camaros. It came into Corvette use for the 1975 model year for L-82 engined Corvettes and was used through 1979 for those applications. For 1975-79 Corvettes used the passenger car and Z-28 oil pans. L-48 used the passenger car and L-82 used the Z-28. The pans are identical in external configuration but the Z-28 pan has some additional internal baffling, primarily to accommodate the 3927136 baffle. The Z-28 pan used for 1975-79 is GM #360450. All 1975-79 Corvettes used 5 quart oil systems. The GM #3927136 baffle is still available from GM to this day. It is pictured in the third photo below.
So, what if you need/want one of the baffles no longer available from GM? Well, the GM #3769768 is available in reproduction. So, that's an easy one. However, the GM #3989075 is no longer available and is not reproduced. No problem, though. All one needs to do is to purchase a GM #3927136, measure 4-1/4" from the end, scribe a line across the baffle at this point, and cut with an abrasive wheel chop saw or band saw. Presto! One has a GM #3989075. If you do this, make sure you de-burr and dress the cut end for safety's sake. A side-by-side photo of the 3989075 and 3927136 is shown in the fourth photo below.
One more thing: some of you may have noticed I mentioned in my first paragraph that there were FOUR external baffles used for Corvette small blocks, but I only described THREE. So, what about the fourth one? That's for later.
GM #3769768. The first was a "flat" baffle plate used for some 1960-61 applications. This baffle was also used for 1963-65 Corvettes with 6 quart oil system as well as some early 1970 LT-1 and all 1970-72 ZR-1. It is pictured in the first photo below. It is designed to work with certain 1960-61 oil pans as well as the 63-65 GM #3820001 and the 1970-72 GM #3956670. This baffle was GM-discontinued in October, 1995.
GM #3989075. This is one that few folks know about. It was a "shorty" curved baffle plate. It was used for 1970-72 LT-1 with 5 quart systems and all 1973-74 L-82. It is designed to work with the GM #3820000 oil pan. It can be seen in the second photo below. This baffle was GM-discontinued in October, 1982 and can be difficult to find.
GM #3927136. This is the "long" curved baffle. It was first used for 1968 Z-28 Camaros, having replaced an earlier baffle used for 1967 Z-28 Camaros. It came into Corvette use for the 1975 model year for L-82 engined Corvettes and was used through 1979 for those applications. For 1975-79 Corvettes used the passenger car and Z-28 oil pans. L-48 used the passenger car and L-82 used the Z-28. The pans are identical in external configuration but the Z-28 pan has some additional internal baffling, primarily to accommodate the 3927136 baffle. The Z-28 pan used for 1975-79 is GM #360450. All 1975-79 Corvettes used 5 quart oil systems. The GM #3927136 baffle is still available from GM to this day. It is pictured in the third photo below.
So, what if you need/want one of the baffles no longer available from GM? Well, the GM #3769768 is available in reproduction. So, that's an easy one. However, the GM #3989075 is no longer available and is not reproduced. No problem, though. All one needs to do is to purchase a GM #3927136, measure 4-1/4" from the end, scribe a line across the baffle at this point, and cut with an abrasive wheel chop saw or band saw. Presto! One has a GM #3989075. If you do this, make sure you de-burr and dress the cut end for safety's sake. A side-by-side photo of the 3989075 and 3927136 is shown in the fourth photo below.
One more thing: some of you may have noticed I mentioned in my first paragraph that there were FOUR external baffles used for Corvette small blocks, but I only described THREE. So, what about the fourth one? That's for later.
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