GM 355 Base Marine Engine • Cast Iron Vortec Heads • Flat Tappet Cam
MBP3550CT - GM 355 Base Marine Cast Vortec Heads
HP & Torque: 365 HP / 390 FT LBS
Compression Ratio: 9.5:1
Cast Iron Heads
Hypereutectic Pistons
Flat Tappet Cam
Cast Steel Crank
Part #: MBP3550CT


Seasoned 4 bolt main block
One piece rear main seal
Max bore .040
Align honed main bearing bore
Sonic tested to assure wall thickness

Rotating Assembly:

New cast steel crankshaft-externally balanced
Chevy heavy beam rods resized and clearance improved
150,000 PSI rod bolts
Keith Black Hypereutectic pistons
Hastings moly rings
New Hydraulic flat tappet camshaft
Heavy duty double roller timing

Cylinder Heads:

GM Vortec cast iron cylinder heads
1.25 dia. valve springs, hardened retainers and keepers
2.02 swirl polished intake valves
1.60 swirl polished exhaust valves
Elgin hardened push rods
Long slot rockers with positive lock adjusting nuts

Cam Specs:

Cam Type: Flat tappet
.480 Intake .489 Exhaust
218 Intake / 224 Exhaust duration
@ .050 - 112 degree lobe separation


Ignition Timing:

34 degrees at 3500 rpm

Also Includes:

New cast iron marine intake

Polished aluminum valve covers
Oil pan
Brass freeze plugs
All engines are dyno tested on a state of the art DTS dyno and ship with a complete spec sheet


12 month unlimited hour on pleasurecraft only. No warranty on commercial use.

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