Cummins Turbo Diesel 4BT 3.9L Custom Intake Manifold Plate Material Thickness:1/4" It's because your stock cover

It's because your stock cover plate with actually move and stretch under boost levels it was not designed to handle

has no steps that block flow in the middle like the old style 2 & 3 piece iron manifolds

These are fabricated using 3/16 CR plate and bent in our CNC automated press brake

4- Long 304 Stainless socket head mounting bolts for the mounting flange thickness you choose

Cummins Turbo Diesel 4BT 3.9L Custom Intake Manifold Plate Material Thickness:1/4" It's because your stock coverHere we have a in house design for all 4BT Cummins 3. 9 Diesel owners. ALL 3 8 AND 1 2 PLATES HAVE A 4 WEEK LEAD TIME FOR PRODUCTION UNTIL MATERIAL AVAILABILITY IMPROVES These intake cover plates are CNC Laser cut from USA made 304 stainless steel for way superior quality and finish. These stainless plates will never rust, tarnish, crack, chip, or oxidize, EVER!!! No more polishing. These have shown no failures on our trucks at up to and beyond 100#