I ran both it seemed to like the tunnel ram the best though. I had problems with it trying to pump to much oil up to the valve covers. The lifter gallery runs under the lifters and since the roller lifters don't move, the lifter oil holes were constantly lined up with the lifter gallery. I turned the lifters upside down and then didnt have any oil to the rockers. So I ground a thin line from the waste of the lifter up to the oil hole until I got the right amount of oil to the rocker arms. I talked to the Crane tech and they were suppose to fix the problem. I'm sure it has it but you have to run a Jack Rouse restricter kit on the blocks main journals to keep oil on the crank. The last 351 I built is still running 11.50s in a 73 Mustang. Owner said hes freshed it 3 times, but other than that hasn't given problems.
How fast is the car the engine is in?