[steve-d]

Obtained the Harland Sharp 1.7 ratio Alum roller rockers. Nice pieces. Went in ok.

Rear part was close to ridge in head and filed it down to give a little more clearance.

No excessive noise or other downfalls.

Steve

[steve-d]

For you guys installing the RRs onto the LT1 motor, don't forget to upgrade the Knock Module (KM) located in the back of the PCM unit. The engine has a knock sensor and its job is to record the "noise" of the engine and send the signal to the computer's KM. The KM interprets the signal and instructs the computer to retard timing when knock is detected.

The OE LT1 KM will interprete the additional noise signal generated by the Knock Sensor (arising from RRs, cam and/or headers & etc) and it will then retard the timing "thinking" that the additional noise is true knock when in fact it is just mechanical noise.

Substitute the LT4 KM for the existing one. GM modified it to account for the added noise produced by the LT4 RRs and higher performance so as to not retard timing w/o true knock being present.

Sold frequently on EBay and elsewhere for about $40. There's a guy I bought one from at a GM dealer for about $35 total. Ten minute swap out

steve