ScottC

Need some help guys/gals. Just dropped off the 71 Cutlass Supreme w/350cid (not sure of the trans that's in it, it's a 3 speed automatic) to have some leaks fixed. They couldn't find a rear main seal except for a rope. My understanding is that a neoprene is a better replacement. Is this correct and if so where can I find one? Have searched the forum w/no luck and also the internet. Any help would be greatly appreciated.

Scott

joe_padavano

There is no "factory" neoprene rear main seal for an Olds motor. The neoprene seal from either an AMC 258 or a Ford 292 Y-block both work in the small block Olds applications. FelPro sells both. Obviously ensure the lip is facing inboard when installed.

Olds specialty vendors will sometimes repackage these parts as "Oldsmobile" parts and mark the price up.

Do not listen to people who tell you that you have to grind off the serrations on the crank journal - these do not ride in the seal when installed.

ScottC

Thanks Joe for the quick response. I went to FelPro's website and Selected "Ford" the "292 V8" and "Passenger Car" application. Looks like there is only one part number for all 4 of the VIN applications. Checking to make sure that Part #BS 6141 is the correct one? Would rather not have to order twice if I don't have to. Thanks again.

joe_padavano

"VIN applications"??? I'm pretty sure a late 1950s VIN didn't have an engine code in it. In any case, yes, 6141 is correct. Ignore the straight seals and wires that come with it - those are to seal the Y-block rear main cap to the block and do not apply to an Olds application.

ScottC

LOL Probably not. Here's an example of what came up: 16 Valve 3.75" Bore Carb 4 Bbl. Gasoline Naturally Aspirated VIN M . I've got it being delivered to the NAPA store right near my house and it will be there at 3:30 p.m. today. Again TYVM for the help it was a massive time saver.

Greg Rogers

Great info! I didn't know that about a one piece seal for our Olds. Thanks Joe.

joe_padavano

Just to clarify, this is not a one-piece seal. It's a two piece neoprene seal that replaces the stock rope seal. It isn't possible to fit a one-piece seal over the crank flange, which is larger than the diameter of the sealing surface on the crank.

Greg Rogers

But still a upgrade from the rope type.