piston questions
My dislike of the 360 goes back to the late 80s, ones I've had and ones dad had, 70s ones that did nothing better than 318s besides more stops for fuel
Well Don, yur not wrong, below about 3000>3600.
And the reason is that the factory low-compression LA-models both math out to about the same V/P, namely , 112 for the 318 and 114 for the 360.
But, the 360 has a cam that is 12* bigger, with 16* more overlap, so it had the potential to carry power about 400 rpm higher, which is good for some 20/25 hp right there, while still being a 2bbl.
and 360 cars usually carry a one or two gear penalty for lower-rpm cruising.
and whereas a stock 318 will not hardly notice headers, with its modest 20* overlap, the 360 with it's 32 or so, will.
Now; I have installed a 360 2bbl cam into a 318 2bbl engine, which, with a small-port intake and 500AVS, resulted in a lil softer bottom, and a much improved top. Adding 3.23s over 2.76s, more than made up for the loss of bottom end.
So, I can whole-heartedly agree with your LA stock-engine findings.
But
I have also taken a hi-compression 340 short, and bolted an entire 318 top end onto it including the 318 cam, and that was a beast, comparatively speaking.
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So, if I had to make a choice, for towing, using factory Magnum parts, I would take a hi-compression 5.9 short any day, with iron Magnum heads, and install a 5.2 cam with a finished SCR around 9.0. The Wallace calculator predicts a pressure of 158psi@900ft, and a V/P of an amazing 150, Perfect for a tow vehicle.
Since you will be running a 5-speed with overdrive, and more than likely
be towing in direct, I think I would like a 5.9, and gear it to tow at a slightly higher rpm with, a lil less ignition timing, then see how that goes. I would for sure run a dash-mounted, dial-back, Timing module, to get her dialed in. With a 5.9, you can put a lot of timing in the VA, during cruise; as much as she wants. So, say you tow at 3000, and bob-tail at 2400 or so; but no less that 2200. Bob-tailing, she will probably like a LOT of VA, into the mid50s would be my guess.
Read about V/P here;
V/P Index Calculation