CYLINDER HEADS & VALVETRAIN

Valve Spring, 32lbs Code: AGK32LBSVS Price: $10.50 Sorry, we are currently sold out of 'Valve Spring, 32lbs'. Please check back later. Quantity in Basket: none The 32lb valve springs. Recommended for mild motors using stock cam. Change quantity to two if you want two springs.

Valve Spring, 55lbs Code: AGK55LBSVS Price: $10.50 Quantity in Basket: none 55lb single spring. Install height 1.200" with 90 to 95lbs open pressure. Use with mild cams. Change quantity to two if you want two springs.

Valve Spring, Dual, 50lb Code: AGK50LBDVS Price: $15.00 Quantity in Basket: none Dual valve spring for high output motors. Install height 1.300" with 50lb seat pressure. 120lbs open pressure. Coil bind at .600". Change quantity to two if you want two outer and two inner springs.

Shim, .029" Code: AGKE356 Price: $1.15 Quantity in Basket: none Use these shims under the valve spring to obtain proper install height.

Retainer & Keeper Set, 390 Code: AGKSRET390 Price: $32.00 Quantity in Basket: none This retainer and keeper set is designed to be used with our stainless steel 390 valves. Will not work with stock valves.

Retainer for Exhaust Valve, 390 Code: EEVR390 Price: $5.00 Quantity in Basket: none Stock exhaust valve retainer. Use on stock intake valve to accomodate lash cap.

Stainless Steel Intake & Exhaust Valve, 390 Code: AGKS31EX-AGKS35IN Price: $65.00 Quantity in Basket: none These stainless steel valves replace the stock size valves. Longer than stock (+.250") to accomodate high lift cams. Must use aluminum retainer/keeper set and lash caps.

Stainless Steel Intake and Exhaust Valve, 390mm +1mm Code: AGKS32EX-AGKS36IN Price: $65.00 Quantity in Basket: none Stainless steel 32mm exhaust valve & 36mm intake valve. 1mm over stock size. Use stock valve seats. Longer than stock (+.250") to accomodate high lift cams. Must use aluminum retainer/keeper set and lash caps.

Valve, 1.5", 390 Code: AGKS38IN Price: $32.50 Quantity in Basket: none 1.5" intake valve for GX390's. Must use larger seat with this valve. Works great with big cams, carbs, etc.

Valve Seat for 1.5" Valve, 390 Code: AGKSVS15 Price: $10.00 Quantity in Basket: none This valve seat replaces the stock intake valve seat. Use the 1.5" intake valve with this seat.

Valve, 1.5" & Seat, 390 Code: AGKSVS15-AGKS38IN Price: $41.00 Quantity in Basket: none Large 1.5" intake vale and seat for high output GX390's. Machining required to install larger seat.

Valve Lash Caps, 390, OEM Honda Code: HON14781390 Price: $10.00 Quantity in Basket: none Lash caps help prevent valve wear. They also provide a larger surface area for the rocker arm. Use with stock exhaust retainers on both stock valves. Price includes two lash caps. OEM Honda lash caps.

Lash Caps, 6mm, 390 Code: AGKE207 Price: $15.00 Quantity in Basket: none Lash caps are required for our stainless steel valves. These are 6mm lash caps designed for our OLD stainless steel valves. Will not work on stock valves. Price includes two lash caps.

Lash Caps, 6.5mm, 390 Code: AGKE211 Price: $15.00 Quantity in Basket: none Lash caps are required for our stainless steel valves. These 6.5mm lash caps fit the GX390 valves sold here. Helps prevent valve wear. Provides larger surface area for rockers. Price includes two lash caps.

Chrome Moly Push Rods, 390 Code: AGKPR390 Price: $30.00 Quantity in Basket: none Chrome moly push rods are highly recommended when using an AGK racing cam.

Chrome Moly Pushrods Unassembled, 390 Code: AGKPR390U Price: $30.00 Quantity in Basket: none Cut to size chrome moly pushrods. Assembled length is 6.680".

Guide Plate, Push Rod Code: AGKE317 Price: $12.50 Quantity in Basket: none This guide plate has larger slots to accomodate the chrome moly plush rods.

Rev Roller Rockers, 390 Code: AGKRR1*390 Price: $215.00 Quantity in Basket: none 1.3 ratio is on backorder. Honda (or clone) GX340/GX390 billet roller rocker arms designed and engineered to withstand the valvetrain stress of a modified motor. dyno tested and race proven ratio rockers choose 1.2 or 1.3 rocker arm CNC machined from 7000 series alloy low rotational inertia mass due to super light arm design bearing grade brass bushings reduce rotational friction precision ground and hardened roller tip provides ultra smooth rotation ground and hardened alloy steel rocker shaft design eliminates valve train deflection cupped lash adjusters with ARP 12 point fastener

Valve Cover Spacer, 390 Code: AGKRR390S Price: $55.00 Quantity in Basket: none Use this valve cover spacer to provide clearance for our roller rockers. New bolt included. CNC machined from billet aluminum.

Shim Code: AGKRR139 Price: $1.50 Quantity in Basket: none Precision ground and hardened shim to adjust the height of your rev rockers. Required when running longer aftermarket valves. Available in .062" and .093" heights.

Cylinder Head, 390, Ported & Milled Code: AGKHPM390 Price: $178.00 Quantity in Basket: none Cylinder head ported and milled. Increased flow and velocity from our porting makes this head an excellent choice for performance and value. Highly recommended performance upgrade for the racer looking to take his/her GX340/GX390 to the next level.

Cylinder Head, 390, Ported/Milled, Big Valve Code: AGKHPM390BV Price: $285.00 Quantity in Basket: none Big valve cylinder head using 1.5" (38mm) intake valve and a 32mm exhaust valve. This cylinder head has been professionally ported after extensive R&D with the flow bench and track time. We mill to your specification. You get a ported/milled cylinder head, 1.5" intake valve, 32mm exhaust valve, new intake seat installed and seats have been prepped. You need to install your valve springs, rocker arms, etc.

Head Dowel, GX390 Code: HON94309 Price: $2.25 Quantity in Basket: none Head dowel for the Honda GX390. Price is for one dowel. Change quantity if you want more than one.

Lifter, Stock GX390 Code: HON14441 Price: $11.00 Quantity in Basket: none Genuine Honda GX390 lifter. Big block motors in the 50hp range are wearing out the stock clone lifters. Use this genuine Honda lifter as a replacement. Sold individually. Change quantity to 2 if you want 2.

Gasket Set, 390 Code: CS390GS Price: $26.00 Quantity in Basket: none Complete engine gaskets set for GX390. Includes head, side cover, valve cover, exhaust and both intake gaskets.

Gasket, Cylinder Head, GX390 Code: HON12251390 Price: $12.00 Quantity in Basket: none Cylinder head gasket for GX390.

Gasket, Cylinder Head, Steel, GX390 Code: HON12251390S Price: $15.00 Quantity in Basket: none Special steel cylinder head gasket. Use with high compression engines. Gasket is .050" thick.