1989 chevy 350 TBI, in 87 Blazer....has heads 14102193 listed with 1.94/1.5 valves for 305/350....will Heads 14014416 listed with 1.84/1.5 valves 58cc chambers for 305 work without any modifications? The walls on the original heads are taller than the 305 heads. But both sets are the same height. The original heads have the valve cover bolts down the center of the head, and the 305's have the cover bolts on the outer edge. The original heads will need to be redone if the 305 heads will not bolt right on. Need input ASAP. Need to get motor running yesterday. 

