what does the cirlce thing at the end of the cam do?

[spinemup]

its an eccentric cam lobe that operates mechanical fuel pumps.... just because you have a fuel injected car that doesn't mean your block wasn't prepped for carburators...all you need is a diff timing gear cover and you can make use of the mechanical fuel pump...i think they left it on the short block assy for people that were buying 302 short blocks from the factory and using them in thier older vehicles. that way they can keep stock alot easier instead of having a shelf of "fuel injected prepped" blocks and "carburated prepped" blocks. they use one short block for both applications