where get engine oil dye for leaks?

[Abydos]

I have a leak in the back of the block of my 340 that Im not sure where its coming from. The oil sender is good, no leaks there or from the valve covers. I recently replaced the rear main oil seal and was careful not to nick it when installing. I couldnt tell if the plug for the cam in the back of the block leaked or if the other oil passageway plugs leaked or not, no evidence as the whole back of the block was oily. I should have pulled them out and replaced them but I didnt, and now the motor leaks more than ever.
Before I go and order another rear main seal and maybe a cam plug, I thought maybe I could get some kind of dye to add to the motor that might make the source of the leak clearly visible, anyone have a source for oil dye? The local auto parts stores dont have anything like this. Maybe machinist's dye? As a last resort, I may replace the rear main bearings with those special bearings with the grooves cut in them to channel oil away from the rear main oil seal that Mopar advertises for 340 in their catalog. Anyone tried these?

[HankL]

You need to go to your local Chrysler dealer and ask for 4-IN-1
Blacklight dye (Mopar part number 05010042AA /cost $8 per tiny bottle) and put this in the engine oil.

It works in coolant and atf too.

Spencer's Gifts stores in malls have blacklight bulbs, and cheap battery powered blacklights are available to spot counterfeit US dollar bills - our new design money has tiny tapes running top to bottom that glow in blacklight.

Another trick to to clean off all the old oil, then spray the clean area with Mennon 'dry powder' underarm deodorant. The white powder film it leaves makes spotting oil leak sources easier.

[Abydos]

I found some online at Napa today, thanks.

[Bigfoot]

That dye is excellent. I was tring to find a gas leak somewhere on my 4 door Diplomat and for the life of me I couldn'tfind it. I put one bottle of the Dye in the gas tank and drove around the block and put the car up on stands. I turned the garage lights out and with a cheap 2.99 black light in my trouble light it showed everywhere that gas was leaking. The line had a small pin hole sized leak right up by the right front wheel. I replace the line and now there is no stink of gas when I open the garage. I also used it in locating a oil leak at the back of my 318. I pressure washed the whole engine and put the bottle of Dye in the oil and drove it home. Same thing it showed right up that the back corner of my intake manifold was leaking and saved me allot of aggrivation trying to locate the leak.

[dartswinger74]

I get mine from the snap on dealer

[ITSAHEMI]

abydos,
check the rear of the motor carefully.a possible cause may be the intake manifold gasket.