Originally Posted by OMARS67
whats the differences between 49 and 781 to other heads?? like 148. i have a set of 049 and 148. the 148 are 396 heads with a 110cc ported and fitted with 2.19 valves. were my 049 heads are stock no porting and 2.08 valve.and a huge 119cc. i measured with a caliper the inside diameter of the intake runner and found the 148 to be bigger. without flowing them i wouldnt know which has better velocity, wich is what i care about. and i really dont see any difference in design.
Most ppl like the 049s as far as round port goes. Rectangle port is also popular option but usally not as important as it may seem.
049 are the larger as cast factory castings. 240cc intakes with 119cc exhuast. They will port well and flow well. 781 have the better shaped ports and flow very good as well. with 225cc intake volume. sometimes better for a low rpm build.
148 are 225cc intakes as well. But exhuast port volume is smaller than on 049.
Here is a look at some stock and after market heads tested. But the stock casting is ported by a pro.
Oval Port Big-Block Chevy Cylinder Heads - The Big O - Super Chevy Magazine