I have an 85 Burban with a newly (8kmiles) rebuilt 350 it sat for roughly 6 years after being rebuilt and driven for about 5k miles. I believe the front main seal is bad as there is oil leaking from behind my alt and fan. It is a small leak where I don't notice it. But when I shift into OD it shoots oil onto my headers and smoke just swallows the rear of my truck. I am wondering if there would be a quick nd easy fix or if it could be something other then my front main seal since it gets worse only in OD. I lost 3 gear and drive in 2 up to 50mph and it doesn't smoke then when I shift into OD it does them stops when i shift out of OD. Please if anyone knows anything to help I'd appreciate it very much

 

I believe you remove the pulley usually with an impact wrench to fix front main.
I fixed a 6.2 Diesel once by dropping the oil pan, reshaping the front of the oil pan a bit and then installing a cheap gasket bingo wasn't the front main. I have done a rear main before wasn't hard. I would make darn sure it just isn't the oil pan and/or gasket maker most use. I use gaskets whenever possible haven't had greatest of luck with gasket maker!

 

On I will look into that. Thanks a lot for the advice