Our 95 Transport 3.8 now has 158K miles. I have had 2 constant fluid leakage issues with this van over the last couple of years.
I was losing about a quart of oil to the ground about every 3 weeks. I searched a number of reviews and found that CD-2 oil leak seal had good ratings. So far, this product really seems to have controlled the leakage. The valve cover gaskets may have sealed with this product. I will update.
The other problem was an on-going coolant leak probably from a warped upper plenum intake. I had previously replaced the radiator and flushed the coolant system very well about a year prior.
After much research, I used 5 Bar's leak radiator stop tablets. They are the same material that GM used. They are mainly crushed walnuts, and very finely granulated. I cannot believe that it actually worked. After what I have researched, the golden seal powder or the Bar's Leak tablets are the ONLY material that should be used in the coolant system.
Fortunately, I may not have to take this engine apart to replace parts and seals. I have done the work installing an intercooler on my GTX, but I have huge misgivings with the electrical wiring problems I have had. I do not want another electrical nightmare....hope this helps others..cheers KEV