[1978CobraII]

I'm building a 70 302 and I found out the stock cam is a Hydraulic Flat Tappet cam. Would I have to replace it with a cam that also is a Hydraulic Flat Tappet or could I use a Roller cam? This is confusing because Edelbrock lists there 2221 cam as a Hydraulic roller and yet it doesn't get filtered out by me putting 1970 in as my engine year on summit.

[Boomyal]

The 2121 is a retrofit roller cam for non roller cam 289 and 302 blocks. The 'kit' apparently comes with everything you need.

Camshaft Kits include: Hydraulic roller lifters and pushrods.

However, I would still call Edelbrock Tech and ask them all the details so that nothing gets overlooked. This cam is not the same as you would use for a 5.0 roller cam engine.

[The Greek]

The lifter bores are made taller on the roller cam blocks. The OE roller lifters are also. To compensate for not having the taller bores, a smaller diameter camshaft is used to place the new roller lifters lower down into the bores. You must use the lifters that are designed to work with the smaller dia. camshaft.