hey, i have a small block 350 with the holley systemax2 heads and intake.
it is running great, but it has got a oil leak coming from the back of the engine running down the bellhousing. i have checked the valve covers, intake and oil pressure sending unit, and they dont appear to be leaking. it will not leak sitin still, you can race it up or anything and it will not leak! but as soon as you pull out and go for a drive it leaks. does anyone know what might be happening, any information would be GREATLY appretiated!

Distributor gasket?

long shot, but there is an oil galley plug in the drivers side deck, you can see maybe half of it peeking out past the head if you look hard. Most likely tho, it's the back of the manifold.

it dont appear to be leaking there, the intake stays dry. the oil just puddles where the casting #s are on the back of the block, i could see about half a hole under the drivers side head, so i took the head off but it is plugged i can not think of anywhere else it might be leaking from?

I had this happen on my '55 the rear intake gasket slipped. Check again.

ok, thanks for the help!! i have tried re-glueing the intake down several times, got any tips or good sealants that would work better than just normal RTV.

RTV black works, but it takes a fairly hefty bead - more than I thought. I chased the same leak, and once I really laid down a thick bead, it quit leaking.

Get a leak detection kit which uses a dye that you put in the oil and can be seen with a UV flashlight supplied in the kit. Makes detecting these leaks MUCH easier. I had the same leak you did and I was able to pinpoint it to the intake manifold.

http://www.tracerline.com/

thanks! everyone for the help.

Justin...I fought the same type issue.Oil leak from the china wall.I inverted the intake manifold and center punched small dimples to help anchor the rtv sealer.Maybe I am to shy on the bead thickness...I just do not like gobs of rtv hanging down in the lifter gallery that can break away.I also tape the intake and block and finger smooth the rtv...then remove the tape for a nice finished look before it tacks up.

i found it to work best fo me is to put a nice bead then just sit the manifold in place for a bit and let the silicone tack up then torqe the bolts down. let it set good at least over night before you mess with it then trim the excess with razor blade. no leaks for me.