This is a big time newbie questions but what are flat topped cams, and are hydraulic cams an alternative to pushrods?


Camshafts
Since we’re assuming you’ve started out with a new or rebuilt 351 short-block, we’re not going to talk about camshaft or timing-chain choices, but there is one important detail that bares mentioning. Early 351W blocks are not designed for use with roller hydraulic cams. This leaves you with two choices: Run a flat-tappet cam, or make some changes so you can run a hydraulic roller. "We find that about 50 percent of our customers stick with the flat-tappet cam," George Klass says. "But that limits you to less-aggressive profiles because of the ramp rates [of a flat-tappet grind]." George says if you want to use a hydraulic-roller cam, you can use stock 5.0 roller lifters as long as you run a small-base-circle cam (also known as a retrofit cam), available through a variety of cam manufacturers

 

there are different types of cams

Hydraulic Flat-tappet
Mechanical Flat-tappet
Hydraulic roller

roller cams ae more efficient and can producer a little more power but you need more then just cam and lifters to use it
hydraulic flat tappet, basically is just a cam and lifters, most people choose this for their old block because their block came with this.

theres also mechanical cams but dont worry about them.

all of them require pushrods

 

so what do all the 351 require?

 

or what are the 351 engines set up for

 

Depends on what year your block is, I believe after 1986 ford 351w went to hydralic roller cams/lifters. You will need to look up the casting numbers on your block to see what year it was produced in