I have the GT40P heads and opting to keep my stock cam in the 5.0 explorer V8. Will I need to upgrade the valve springs as well with these 1.7 roller rockers or will the stock springs work just fine? Thanks
You'd want to upgrade the springs. The stock springs were barely adequate for the stock cam and 1.6 rockers. Adding the 1.7 roller rockers could cause valve float at relatively low RPM. The TFS-2500100 would be a great option for you.