In my view 'docile' could mean power brakes should still be possible. But of course an elec. vacuum pump could take care of that perhaps these days.
Of course 'Docile' is easy to interpret differently for anyone.
Let's say, could you wait for 5 minutes for a traffic light?
How about 10-15 minutes of idling in a traffic jam, all without overheating or fouling plugs?
Powerbrakes could be made to work with a vacumpump or possbily hydroboost.
My old 340 with a 260+@.050 solid roller didnt have any problem what so ever with a 8hour lap around Västerås during a very warm cruisenight at PowerBigmeet, Thing was pretty much runing at a 800rpm idle for 8 hours straight except for one occasion when i got of the cruise to get some fuel and found myself alone on a empty street where i gave it one big step on the loud pedal and the thing sure responded just like usual.
Thing didnt even have a huge colingtsystem,just a radiator out of a 4cylind Ford Scorpio and a MRGasket 16" electric fan and never ran hot at all despite what internet toughguys tried to tell me and that was with a tallfilled block.
In my opinion its mostly about having an happy combo that is well tuned to stay out of trouble with heat and fouled pluggs.
I’m gonna say the xe256 cam and 302 heads aren’t the kind of items I’d be seeking out to use if the goal was truly 500hp.
Maybe with some boost.
The sidewinder heads flowing an honest 265+, a small roller like a Comp XR280R, with the other stuff you already have should get you close.
Not sure how the propane fits into the equation as far as power output goes.
Thats not a bad idea you have there,if those sidewinderheads are real efficient and everything else is just right they might just reach close to 500hp with that cam,
Thats actualy the last cam i ran before my worn out 340 finaly expired it sure has a long flat powerdelivery ,Its a very nice running cam in a stock stroke 340 and might be even better in a 360.
