85 Degree Risers & Manifold

90 Degree Risers & Manifold

Tail pipes extra on both sets

IMCO’s - PowerFlow Plus Exhaust System

High performance marine engines are growing in size 510, 540,
& 572 c.i.d. motors and larger, naturally aspirate and blown, are
becoming increasingly popular. But, until now, there hasn’t been
an efficient or affordable high performance marine exhaust system
specifically engineered to accommodate these “monster motors”.
The answer, however, is IMCO’s totally new Power Flow
Plus cast aluminum fully water-jacketed exhaust manifolds.

P/N PF- 84K Plus Black
P/N PF- 84K Plus Polished

Tail Pipe Gasket - P/N RGKS

Available in Black or Polished. Black manifolds and risers are hard-coat
anodized inside and out to withstand the tough marine environment.
The new PowerFlow Plus features IMCO’s innovative patented design
with 33” internal runners and a new ultra hi-flow exhaust riser
(custom stainless steel tailpipes and integrated mufflers available). Is it possible that a cast aluminum water jacketed exhaust manifold can
match or exceed the power output of racing style dry-stack collector headers?

P/N PF- 85K Plus Black
P/N PF- 85K Plus Polished

Riser Gasket P/N RGKP


P/N TP-82KB Black BB
P/N TP-82KP Polished BB
P/N TP-S82KB Black SB
P/N TP-S82KP Polished SB
P/N TP-V82KB Black V-6
P/N TP-V82KP Polished V-6

IMCO’s affordable alternative to stock cast iron Chevy
manifolds and risers. Our all cast aluminum manifolds and
risers will increase Horsepower, RPM, and Torque by 5 to 7%
over stock cast iron manifolds and risers at a fraction of the
cost. We have designed Thumper Power for everyone
whether you’re a high performance or family recreation
boater. Kits are available for Chevy big block, small block, and
V-6 motors. Available in black powder coated, optional hard
anodized for corrosion (prior to powder coat), and polished.
Shift, EFI, or ECM brackets sold separately. When using these
manifold and riser kits, it’s best to order 2 each of FH-67V
oval hoses for wishbone connections.

Manifold to Riser Gasket P/N RGKT .. Shift Bkt R.H. Side P/N CB-88TPR .. EFI ECM Bkt Left P/N CB-88TPL Manifold to Riser Seal P/N RGKC

4” With Flapper
P/N ET-624F

BB PS & Alt. Bracket
P/N PSA-111

Timing Cover

P/N TC-54 Mark IV BB
P/N TC-53 Gen V BB
P/N TC-52 Gen VI BB

Thru Transom Exhaust
P/N ET-65 4”



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