I was thinking about installing a set of Trickflow 23* heads on my stock bottom end along with the LT4 hotcam kit (.525" lift int. and exh. with 1.6 ratio rockers). I heard that the exhaust valves on the trickflows can lift to .525" befor hitting the piston. Is this true? If so, then would I be fine using this kit, or would the clearance be too tight? Any alternatives to the LT4 package if this is the case? I am trying to run high 12s on a budget. In addition to the mods in my sig, I have a 2500 stall, portmatched plenum, edelbrock runners, and edelbrock base manifold. Also, the trickflows are mildly ported. Thanks for the help.

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1990 Firebird Formula 350 speed density TPI; K&N, air foil, throttlebody coolant bypass, underdrive pullies, MSD 6AL, MSD HEI coil, 8.8mm wires, , Hypertech Stage II chip and AFPR, 160* thermostat, fan switch, B&M stage 2 shift kit, Edelbrock 1&5/8 headers, !Cats, !AIR, Flowmaster 80 series muffler, 3.73 posi rear end

Just bought Edelbrock base and runners and mild ported TFS heads for $1075 that I will install with a matched cam! 12s here I come!

 

Why not call trick flow and ask ?? Also.. what kind of springs do you have on the heads ? The small 1.25 springs wont take 525.

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92 Z28 5.7
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Trick Flow 23° heads, Comp Cams XR270HR-10 cam, Accel intake base + ported TPI,
TES headers, Flowmaster catback, MSD ignition, #24 SVO injectors, 1LE aluminum driveshaft.

Click here to see pics of my car !

 

most cam/head combos i've check don't have a piston to valve clearance problem untill over .625 lift, with flat tops. it's always best to dummy a head up and check and doesn't cost anything to do or take much time.

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ICON Motorsports
1st & 3rd
MM Black Diamond 538 F&AM

 

Lift isn't the only factor in piston/valve clearence. Duration also plays a factor. You SHOULD be safe, but why not dummy up the head on the motor (with gasket, but only torque to 30 ft/lbs) with a glob of play-doh on top of the piston valve reliefs and give it a couple revs by hand and check the thickness of the stuff. Trick flow sends all this info with their heads.