Steve C , a Man of my Heart!   The Man I  know with # 14 Howard 500 told me of a Howard near Davis.... Chico is same area no?  A Howie with no motors,  George told me was a 250, the Lodestar conversion.  I know I already said it,  but there is still confusion  amongst many. The 500 was not a Ventura comversion.     Ventura was 350 Super Ventura.... There was one 400 built which was pressurization conversion on Super Ventura,  where Dee & Ed realized They would have to build the airframes to achieve Their desired potential.... 500's fuse formers were every 6" and wings built wet,  reshaped for higher altitude.... Sea level cabin @ 16k!
Steve,  if You know of a 350 super,  I would love to see some photos...... Out of 60 350's, I haven't been able to locate any.  Came across a great story about one,  briefly... DEA popped one hauling weed in mid 70's, requisitioned the bird for their own use and had a ball chasing down twin beech,  twin bonanza,  206, DC-3 etc.... They painted it black,  white cabin roof and trim colors were tasty layout,  meant to look badder.  Anyway not too long ago some bean counter pipes up & asks whatever happened to that 350 you guys confiscated & requisitioned?   One cop looks under a lamp,  another cop lofts paper work off his desk,  they both scratch their heads and say to bean counter, "darn, it looks like we misplaced it. " That was the official quote that went into the official report..... 
Some cop got himself a  Super Ventura and has it stashed somewhere in this world.  The 500 I'm connected with is for sale and it's a runner @ half TBO. Those are TWO stage blowers on those 2800's, lots of spares.... 
figure 1.5 - 2M to get back to C of A, but to go unlimited racing @ Reno....... Clay Lacy entered a DC-7 in 71 Cali 1000 unlimited @ Mojave,  He placed 6 out of 16, flew the lowest and turned tighter than the A-26, throttled back when the warbirds had to pit. His avg was 325mph and winning Sea Fury was 344mph.  Proves I can race my motorhome and a Howard 350 or a 500 would be formidable competition for Reno.  Know anybody that can play this Bird(500) I'll get You hooked up with owner.   Peace,  bc