I want to sell my LT1 stock heads with the springs and nsa guides, but I can't find out what the rates were good to on these springs, so that I could provide that info to the buyer. I have had them for over 3 years and IRS is no longer around. I've tried to search on the info but to no avail. All I remember was that they were from the "Terminator" valvetrain package and they were a good fit for my cc305 and 1.6's. Thanks for any help.

 

The "terminator" series springs were actually GMPP springs just repackaged with their naime on it. In most cases the box they were in was still the original GMPP box that IRS just put a sticker over. I used those same springs on my cc305 for a couple years too. Worked great and never had any issues with them. I dont remember the exact physical specs but they were good for .560 lift installed on stock seats.

its funny you posted this because I just sold my old set of these springs. I didnt measure the OD of the springs but installed at 1.750 they were easily good for the .544 lift of the cc305/1.6rr combo. A really good choice in valve springs for that cam.

 

Thanks alot brotha I never recalled it being a GMPP, either way, that'll do.