This is all new to me and to be honest Im not at all familiar how things are calculated. What I know is 72 and newer engines became low compression due to emissions coming around. After hearing this I looked into this cam that says its a simple drop in with increased benefits based on their claims noted below from there web page. Again this is a 318, if I really wanted power id go with a 360. Like I mentioned I want to see If this might give a little more response than stock and sound nice even if it does not make up for it with the power. Not looking for something to launch at green lights or take to a track. All my components seem to match up except the intake ports being bigger on the manifold than the head.
Here is the info from Hughes engines:
"Whiplash cams are designed for the very low compression Mopar O.E.M. engines such as all the 318's, 360, 400 and all 383 & 440's built after 1971.
The factory built these engines with a combination of low compression and cams that produced very low cylinder pressure and low power (see this tech article CLICK HERE). Normally, to increase the cylinder pressure in these engines you would have to disassemble the engine, buy new pistons & rings (at a minimum), rebore & hone, rebalance and reassemble. And then you would still need cam & lifters. The cost of this build-up could easily be $2,000.00 or more and take 2-3 weeks.
The unique design of the Whiplash cam will accomplish all of the same results for as little as $340.00 (cam, springs & lifters) and take about one Saturday afternoon to complete. The Whiplash cams are designed, like all of our "real" Mopar cams to take advantage of the .904" lifter diameter which increases the area-under-the-curve, for more breathing time. However, with low lifts (yes we consider .520" low lift) so that you do not need to remove the heads and machine the valve guides.
These Whiplash cams have become one of our top selling items and we have customer that want to put them in engines that are not low compression. The problem is that the cam will still raise the cylinder pressure and your engine may then require race gasoline or a mix of pump and race gas. As a general rule of thumb engine with a true measured compression ratio more than 8.9:1 with iron heads or 10:1 with aluminum heads should not expect to be able to run on just premium gas. And, whatever you do, DO NOT retard the timing to "make it work". That will "work" and also reduce your power & torque considerably. You'll be sorry!"