joshdillon
Shuamanator
Hello! Anyone running Kooks 2” primary headers part # 10241650 for a 351w Mustang in a Gen 1? Will they fit?
My engine builder tells me we need bigger exhaust primaries to support 20psi. The head is trying to lift and the burn marks in the cylinder shows insufficient exhaust flow. Current combination in Gen 1 truck:
Dart 351w stroked to 422
Trick flow 61cc 206cc R heads with Box R intake and 75mm TB (upgrading to 90mm)
1 7/8” Accufab Mustang 351w mustang long tube headers
Vortech YSI-B
Trick Flow Race Heads Flow
Part no. 52410005-M61
R head flow rate I/E
Actual @28"
.400 245.6/196.7
.500 284.3/252.4
.600 311.9/267.1 (84% is 262)
.700 323.6/275.2
Corrected
.400 238.9/189.6
.500 276.2/241.1
.600 303/253.8 (84% is 254.52)
.700 314.3/260.7
I would think the 1.6 exhaust valve would be the restriction and 1 7/8 primaries should support plenty more than current 800 wheel. Been searching for days and Kooks seems like the only option vs custom headers and they can’t tell me if they will fit the gen 1. Kooks is no longer building custom headers.
Who else can build a set of 2” primary x 3.5 collector headers for 2.75 exhaust pattern without having truck?
Sent from my iPhone using Tapatalk
My engine builder tells me we need bigger exhaust primaries to support 20psi. The head is trying to lift and the burn marks in the cylinder shows insufficient exhaust flow. Current combination in Gen 1 truck:
Dart 351w stroked to 422
Trick flow 61cc 206cc R heads with Box R intake and 75mm TB (upgrading to 90mm)
1 7/8” Accufab Mustang 351w mustang long tube headers
Vortech YSI-B
Trick Flow Race Heads Flow
Part no. 52410005-M61
R head flow rate I/E
Actual @28"
.400 245.6/196.7
.500 284.3/252.4
.600 311.9/267.1 (84% is 262)
.700 323.6/275.2
Corrected
.400 238.9/189.6
.500 276.2/241.1
.600 303/253.8 (84% is 254.52)
.700 314.3/260.7
I would think the 1.6 exhaust valve would be the restriction and 1 7/8 primaries should support plenty more than current 800 wheel. Been searching for days and Kooks seems like the only option vs custom headers and they can’t tell me if they will fit the gen 1. Kooks is no longer building custom headers.
Who else can build a set of 2” primary x 3.5 collector headers for 2.75 exhaust pattern without having truck?
Sent from my iPhone using Tapatalk