Product Description
Part# 19474030 & 19574030
Material: 355-T61 alum alloy
Comb Chambers:121cc
Intake Valve Dia: 2.300”
Intake Port Dim: 1.760”w x 2.500”h
Int Port Location: Stock
Intake Gasket: Mr. Gasket# 121
Exh Valve Dia.: 1.880”
Exh Port volume: 138cc
Exhaust Port Dim: 2.000”w x 1.740” h
Exh Port Location: Raised .300” STD bolt pattern
Exhaust Gasket: Fel-Pro 1412
Exhaust Head Bolts: 1” longer than stock (4) ea.
Flow, Intake: (335) 400 cfm (355) 415 cfm @.800 lift/28”
Flow, Exhaust: 303 cfm @.800 lift/28”
Head Bolts/studs: Bolts – ARP# 135-3603 Studs – ARP# 235-4103
Manifold:Rect. Port Dart (opening – 1.575”x 2.250”) 6.25” tall
Milling:Min. 110cc. (.005” = 1cc) Flat mill only.
Pistons: Most aftermarket pistons.
Push Rod length: Avg. +.200” / +.250” Should always measure
Stock length Int. = 8.275” / Exh = 9.250”
Push Rod Guide Plate
Must use Dart PN# 27001230-4
Retainers: 1.625” – Tit / 1.550” – Moly Steel (10°)
Spark Plug: .750” reach, gasketed. Autolite AR3933 Street AR3924
Spring Cups: 1.625” – .035 cup / 1.550” – ID locator Spring Pockets
1.740” OD for 1.625” cup (.030” deeper max)
Springs: Our Assembly: 1.625D = 275# @ 2.000” / .850” max P.S.I
Valve Angles: Int – 24°, Exh – 15°(Rolled 2°) 4°ant
Valve Length: Int – 5.505” (+.250) Exh – 5.435” (stock)
Valve Stem Dia: .3415” – 11/32”
Valve Train: STD BBC 7/16” stud mount
