MILLING THE HEADS
Senior User
Joined: Aug 2002
Posts: 106
Likes: 0
From: Blountsville USA
MILLING THE HEADS
When I made my 360 into a 390, the stock 360 pistons were about .125" below the deck. When I put in the 390 crank, I looked up the pistons for FE engines by their pin location and found some that would put the piston flush with the deck. My comp ratio ended up at 9.8:1. I wouldn't go any higher than that for sure if the truck is going to pull any load at all. I can run 87 octane, but it pings pretty bad. It even does it some with 93 octane if you run it hard enough. If I had it to do over, I would have went with a lower comp.
Logistics Pro
Joined: Feb 2000
Posts: 3,565
Likes: 9
From: Sun River St. George
MILLING THE HEADS
Geeze I forget all the numbers now Fellas but Silvolite 1130 pistons and 72cc chamber heads should get about 9.5 to 1. If it rattles on regular either back off the timing a bit and or re jet the carb to run a little richer. Thicker or thinner head gaskets are also an option.
William in Atlanta
William in Atlanta
