Power gos with the higher compression as the motor plus the weight load you'll never be buying regular gas for that beast. 89,91+ octane gas and the price at the pump these day has stopped a lot of fun cruising times. As my last motor was a 67 390 car engine. Never got over 10 mpg at best Had to run the timing down to 0 TDC-2*ATDC
whit out pinging . Now sold the camper changed to a new motor with 8.7 ratio running regular cheap gas of 4.29 a gallon now so something to give some thought..
orich