Here is another piece to the puzzle. I went to FelPro’* parent site, federalmogul.com - poked around and found their online catalog: I checked every gasket specified for the 3800 Series II LIM from 1995 to 2003, and found only 4 part numbers:
MS95809 1st design w rubber end seals without locating pins exc supercharged 95-97
MS95977 1st design w rubber end seals without locating pins supercharged 96-97
MS95809-1 2nd design w rubber-plastic end seals w locating pins exc superch 97-03
MS95977-1 2nd design w rubber-plastic end seals w locating pins supercharged 97-03
2 for the L36 and 2 for the L67. All four are listed for 1997 models. That must be the year that locating pins and holes were added. But not for the gaskets – for the end seals. I think the gaskets always had locating pins, and all SII heads have holes for them. It is just like the description says: “rubber-plastic end seals with locating pins.” Don’t know why I didn’t read it that way before. I think GM changed the block in midyear 1997. This could explain why bugsi and bignews1 were spec’d different gaskets from GM for their '97'*.
If you look at the end seals that jr’s3800 got for his 1995 and compare them to the end seals bignews1 got for his ’97, you will see the difference. If this is correct, the question is: Will the end seals interchange? Or, more specifically, can the new end seals w pins be made to work on the earlier engines? I hope so. Maybe Ben can find an old design end seal somewhere to compare when he installs his new aluminum gaskets this weekend.
Are those new (red and black) end seals a little shorter?
Jr's3800 LIM gaskets for his '95. The end seals should be the GM equivalent to FelPro’* MS95809. Notice they are rubber with no locating pins. (At least, not that I can see in the pic.)
bignews1 LIM gaskets for his '97. The end seals should be the GM equivalent to FelPro’* MS95809-1. They are plastic-rubber with locating pins. (You can see the pins in the black plastic on the underside of the seal on the left side of the image.)
Now all we need is some pics of the early and late end rails to compare.
Any help out there?