my77project

So the previous owner put dual valve springs in the engine of my 77 stang (302) I'm in the process of doing a full rebuild of the engine, so my question is, is having the duals on there going to sacrifice the longevity of my engine. in particular I know that some places say that they will kill the camshaft. While I do want a decently high performance car when it's all said and done, I'm not really looking to do drag, or run my car up to 7000 rpms too often. I'm more interested in having a good performing car that I can use as my daily driver. So would it be worth my while to switch those out, or will it not make a big difference as long as I kill the gas pedal too often? Thanks

my77stang

well, i'd say you need to find out what kind of spring pressure you have with those springs. im sure you will be taking the heads to a machine shop for a valve job right? just ask them to check what the installed pressure is. stock is around 80, and 100-120 is where most street performance cams like to be. if these are where your pressures are you are fine, they will not be too much for the cam. may i suggest you using a summit cam, specs are 218/228 .471/.471 they are only like 90 bucks for the cam and lifters and will REALLY wake your motor up without costing you drivability. I had one in a mild 302, it idled well, drove well, and would destroy the tire when i wanted it to.

my77project

probly not gonna take it to a machinist, as it is all brand new. it's edelbrock performer heads and they have practically zero miles on them, so I figure everythings probly in good shape there. I believe they are rated at 125, but I"m not sure. That's my best guess, as I'm not 100% sure which springs they are, but the look like the lunati ones that are rated at 125. btw, where are you getting that camshaft w/ lifters for 90 bucks? I get like 125 wherever I look.

my77stang

you cant speculate as to what the spring pressure is just by looking at them, they could be 100 lbs different. however, edelbrock performer heads would have about 120 lbs of pressure so your fine.

here's the cam

http://store.summitracing.com/partde...amp;N=700+150+

its a proven performer for mild applications

Colorado_Mustang

Depends on the cam what kind of a spring you want. If you change the cam, you'll want to get matching springs. Are you sure it's actually dual springs, or is the inner spring a damper? Mine are the latter and can be confused as being double springs.