I'm putting in 18 lb valve springs on my HF 6.5 clone but was curious as to what the stock spring force is. Anybody know?
As Lefty said around 10 lbs... But we have test a few sets at 8lbs up to 13lbs and of course both springs are not equal tension, Usually 1 to 2 lbs off.
Thanks for the responses!
Do you agree that 18# is the way to go with a de-governered, pretty stock engine with the billet flywheel, header with muffler, and hi flo air filter?
you'll be fine with 18lb springs.
it'd be a good idea to get a billet rod too since you removed (bypassed?) the gov. if you only bypassed it, you have to remove it anyways to install the rod.
PS I had to look up your username...adrenaline!
drill the main out with a #65 (.035") drill this will give you a #90 jet. I also drill my slow/idle jet with a #77 drill. This reduces the deceleration popping and easier cold starts