Flowmaster AMERICAN THUNDER 817662 Installation Instructions Manual

409S Stainless Steel
Removal:
1) Remove the four bolts at the rear of the catalytic converter and remove the existing exhaust system
from the vehicle from this point back. Unbolt the factory hangers at the rear of the mufflers; these will not be
used with the Flowmaster system.
Installation:
1) Place the provided HA572 rubber hanger onto the wire hanger of Y-pipe assembly 86105S as shown in
photo 1 below. Place the 86105S into position behind the catalytic converter and support with a stand, using
four of the 3/8" nuts, bolts and lock washers provided, secure the two flanges together. Also secure the HA572
rubber hanger to the two holes in the bottom of the cross member using two 3/8" nuts, bolts and lock washers
provided.
2) Place a provided clamp onto both outlets of Y-pipe assembly #86105S. Place one of the supplied
HA602 rubber mounts onto the wire hanger of right muffler assembly #842554-321. Place the muffler
assembly onto the back of the Y-pipe and slide the two pipes full together, support the muffler with a stand.
Using a supplied 3/8" bolt, nut, washer and lock washer, bolt the HA602 hanger to the hole in the frame above
the muffler outlet.
Installation Instructions for:
SYSTEM #817662
1975-1979 CHEVROLET CORVETTE
5.7L · V8 ENGINE