I know, this 28oz/50oz external balance question seems to come up a lot, but mine is a little different. Not much, but a little.

From what I know, all 351W's left the factory as 28oz externally balanced engines. Good so far - but I need to make sure the factory parts I'm using from different sources (eBay, swap meets, etc) to put together my 351W are actually 28oz components.

The flywheel (NOT flexplate, FLYWHEEL) is a factory part, 13.75" overall diameter, 164 teeth, casting # E8TR-BA. It is drilled for 3 different size pressure plates.

The harmonic balancer is a factory part, casting/part number is very hard to read, but appears to be D2AE in one section of the outer rim, and 0818B2A (this is the part that's almost impossible to read) in another section of the outer rim. It has the 4 bolt pulley bolt pattern, and the pie-shaped weight cast into the back side that takes up about 90 percent of the inside rim. Looking at the back of the balancer with the keyway slot at the 12 o'clock position, the weight extends from roughly the 5:30 to about the 9:30 position.

I've tried searching on Bing, Google, Rock Auto, etc for definitive descriptions or pictures that show beyond a doubt the differences between 28oz and 50 oz flywheels and balancers, but haven't found a clear, concrete answer.

 

Down in the small block engine section a "Sticky" leads you here: Ford Flywheels and Flexplates
May help some.

 

local ford dealer?
local grey haired, denture wearing ford mechanic?
"xctasy" from Down-under over @ fordsix.com. he gave a tutorial a yr or so ago on ford FW from around the world. should know this 1. pic would B best 4 him to ID, then tell U what U need...