The 10147898 heads were used in late 1980s and early 1990s Chevy light duty trucks. They have a large 76 to 78cc combustion chamber and small valves. Let’s also take a look at your cylinder heads. The casting number on my cylinder heads reads 10147898 : It appears these are 1995 through 1998 350ci crate engines, 78cc chambers, with 1.84/1.50-inch valves.Īre these heads okay to use? I’m also not having any luck making a decision to choose the proper cam. I am building a mild street engine and researching my existing heads for air flow.