Original L-88 oil pan

[Steve Antonucci]

Hi everyone,

I have a question for the big block crowd:

Recently, I purchased an L/78 engine complete from carb to oil pan. The seller
told me he had it in a late 1960's Corvette at one time. He added that he
installed a "special" L-88 oil pan on this engine and I was wondering how to
tell if it is indeed an original L-88 oil pan. I am assuming that the L-88
oil pan was different than the L/71 oil pan.

Can anyone set me straight on this.

Thanks,
Steve

[Joe L.]

Re: Original L-88 oil pan

Steve------

For any given model year, there was absolutely NO difference between the PRODUCTION Corvette L-88 oil pan and the oil pan used for any other Corvette big block, L-71, L-68, or L-36. For any given model year, they were completely identical. There were some very slight revisions in the Corvette oil pans over the 67-69 period, but they are inconsequential and unrelated to which engine they were installed on.

[Steve Antonucci]

Re: Original L-88 oil pan

Hi Joe!

Thanks for responding. I guess I was mistaken. I was of the opinion that
the L-88's used a higher capacity oil pan and that they had some special
internal baffling or "trap door" setup.

Steve

[Joe L.]

Re: Original L-88 oil pan

Steve-----

The oil pan used for ALL 1965-74 Corvette big block applications had welded-in internal baffling and had a hinged, spring-loaded "trap door". In conjunction with this arrangement, an external windage tray was also used. The oil system capacity with this pan was 6 quarts.

So, how much more complicated could a PRODUCTION wet sump oil pan system get? The only way to get more oil capacity would have been to install a deep-sump pan, something that GM would never have done for a PRODUCTION engine in those days. The Corvette oil pan was PLENTY "deep sump enough" for a PRODUCTION engine. I'll bet that Chevrolet engineers concerned with PRODUCTION-validation were concerned enough about the prospect of road debris damage to the pan as it was, let alone making it deeper (and, closer to the road).

Of course, someone wanting to race an L-88 (or, any other big block) might have decided that they wanted a deep sump style pan and could have installed one for racing purposes. There was no "GM law" which prevented an owner from doing this and it would have been very simple to do. Such pans have been available from sources like Milodon and Moroso for many years. As far as I know, though, there was never available such an oil pan from GM as a SERVICE-only item. I wouldn't rule out that such a pan might have been available, but I have no information indicating it was so-available.

[Michael H.]

Re: Original L-88 oil pan

Steve, Joe,

There actually was a GM deep sump pan for big blocks. It was a service only part and had a new lower portion welded in place that added a few extra quarts. I don't remember the part number but it was a very common part in the 60's and 70's for drag racing. Probably discontinued in the late 70's.

[Michael H.]

Re: Original L-88 oil pan

Found the original part number, 3879633. This part was listed in the HD pages of the P&A only. It was originally designed and scheduled for release in mid 1966. It was listed as a 6 qt pan (+1) but it actually increased the total to around 7 1/2 quarts.

[Clem Z.]

i have one here someplace and i think they were

HD truck pans. it stuck down pretty far so we welded 1/8" steel skid plates on them. they sold a matching oil pump with a welded on pickup for this pan

[Steve Antonucci]

Re: i have one here someplace and i think they wer

Mike & Clem,

I'm betting that this is what I have. Based on the comments from the
original owner of the engine, he sure did posture that the oil pan was
special. Also, he built that Corvette for racing, so it fits....

Steve

[Michael H.]

Re: i have one here someplace and i think they wer

Steve,

I'm almost certain that this is exactly what you have. The 3879633 dropped sump oil pan was quite popular for the drag racers in the 60's/early 70's. The GM parts book never listed the number in the standard section of the parts book but it was in the HD pages. The description in the GM book was vague and it never mentioned the fact that it was an increased capacity pan. However, many of the hot rod type magazines of the era often mentioned this oil pan, along with pictures that showed the dropped sump. There would have been one continuous weld bead around the circumference of the sump area, about three inches above the bottom. Most aftermarket drop sump pans will have two weld beads instead of one because these pans just had an additional strip of metal inserted around the sump area. It was specifically designed for racing and had no other application.