I just got a set of iron gt40 heads and f303 and the heads have the .542 trick flow springs in them. My question is if I buy these springs will they work with the rest of the trick flow kit. I want to put the 1.7rr in them as well but dont want to max out the springs I have. Or do you have any suggestions for a .550 lift spring?
Joshua, these springs will work with the heads you describe but I would strongly urge you to check the piston to valve clearance. With the F cam and 1.7 rockers and not knowing the valve sizes we are guessing really on clearance. According to the specs these valve springs are good for .600 lift cams so .550 should be no problem.