Premium Dual Valve Spring kit,OPTIMIZED reproduction from GM 1967-1972 camaro Z28 now discontinued.

As a recap the factory spring used on the 302 by GM and solid lifter LT1 350 Z28  in 1967-1970 was 85 lbs closed pressure and right at 200 lbs open pressure. The GM #142 off road spring most people think was the stock spring was 135 lbs seat closed and right at 280 lbs open, but in truth this "142 offroad spring was put out by GM for only racing purposes "off-road".

Includes Heat treated 4140 Moly Hardened Retainers w/ hardened heat treated Locks

This kit allows for proper flat tappet valve spring pressures which is near impossible to get in 2024! We have tested many aftermarket springs for SBC and BBC Chevrolets and they are all that we have checked higher than their published pressures, which are too high to begin with. This is asking for flat tappet camshaft problems. 

This is for small block Chevrolet to .485 lift. Installed height 1.700-1.750 depending on camshaft lift. Coil bind 1.200. Seat pressure 85-110lbs closed and open pressure 200 - 225 lbs open. 

A spring you can trust to not be excessive and to be correct in pressure for hi performance hyd or solid flat tappet camshaft applications. We also offer trust worthy GENUINE GM hardened face lifters and usa made sold and hyd camshafts for Z28 corvette and others. Inquire for more information.

Beware of most valves springs marketed as "Z28 valve spring .500-.550 lift". They are coming in with way more pressure than advertised, when checked around 350 open pressure and also excessive seat pressure. So, running most if not all aftermarket springs in union with the poorly made modern aftermarket lifters, one can almost be sure to have cam/lifter failure at break-in or shortly after even when using correct zinc fortified oils and proper break-in procedures. 

We through years of testing using the genuine GM hardened face or hardened wafer lifters we also offer in addition to these spring kits you can almost be certain to avoid these problems that are plaguing most people running a flat tappet camshaft. We also offer the correct valve spring kits for small block along with cam and lifter kits for both small block and big block. Inquire for more information.

*Ebay photo is example image for illustrative purposes only. Kit to ship may appear different in color of keeper locks etc.