Have you considered running the stock 318 2bblcam?
It will make fabulous low-rpm torque to go with those 3.23s, with the addition of nothing but a higher stall Convertor. I like the 2800; but for fuel economy, I would maybe choose a 2600. Cuz with your tires and gears, 65=2650 at zero slip, maybe 2730 tops, cruising at 3% slip. Naw, I'd still go with a 2800.
Here's the thing;
any cam with a later closing intake valve than the stocker, will loose low-rpm power, because of the loss of cylinder pressure. You are blessed with an already 9/1 compression engine, so yes you might be able to give some pressure away; but with just 3.23s in the back, I sure wouldn't do it.
IIRC the stock cam is 240/248/112 advertised; in at split overlap the Ica will be 50*
AS for the XE252H, the advertised on that is 252/252/110 and 206/
[email protected] The Ica at split overlap comes to 56*
That's only 6 degrees difference, but the pressure, with no other changes, is predicted to fall from 157 to 149 psi, making your low rpm soft all the way to a breakeven point somewhere around 3000 or a lil higher. in your combo, 3000 is around 25mph at WOT.
You said;
So is losing bottom-end torque a good thing?
How much difference will it really make?
Well the Wallace predicts a P/V index of 131 with the factory cam, compared to 119 with the XE252. That is a loss of 6.3*, which will feel like a loss of 8.1% cubic inches. Making your 318 feel like a 289. read about P/V here;
V/P Index Calculation
The only way around the pressure loss is to increase the Scr(Compression Ratio); but you didn't mention that.
Well there is a second way, which is to advance that XE252 cam 6 degrees to math the Ica of the stock Chrysler cam ; but this trades away power extraction to get compression, not really a good idea in a cruiser. To get the extraction back you would need a split pattern cam of about 6 more degrees duration on the power stroke. But I don't think anyone would grind you a funky cam like that.
The point is that the 2800TC will give your stock-cammed 318 a huge increase in bottom-end that no 252 cam can match.
Now, if you did both, lol, I would install that XE252H in a heartbeat or even any good used 360 2bbl cam...... which is also a 252, lol.
Happy hotRodding
