Got a tune from pcmforless but I will be getting a dyno tune here in Ludlow at the dyno here.

 

here is the pictures of the LT4 springs....

http://home.comcast.net/~grygst76/

 

notice a slight little loss of lowend torque, but a pretty decent gain up high with the new springs...tonight raced a 2004 vette vert and watched him read my back license plate

 

The problem with 987 springs are the locators that are supposed to be used with them. THe springs actually fit just fine in the head seats. THe locators are too large of a diameter which means either machine heads to accept larger locators(what most ppl do b/c the heads are getting ported at the same time anyway) OR you can machine the locators to fit down flush in the seat by notching it where there are clearance problems... that is what I did and MANY hard miles later I have no ill effects.

 

Another thread stated that 4785-16 seats will fit the 1.46O.D. springs and the LT1 heads without machining.