Dwayne@Andy,After getting my TF heads I realized I had ordered the wrong springs for a roller cam, came with flat tappet springs, so I needed to change the springs, so I elected to go with the PAC 1225 dual spring which is 250# on the seat @ 2.00 but will be installed at 1.950 which will increase the seat pressure to 282# and open pressure will be 726# with the .690 cam plugged into Pac's calculator,,do you see any issues going this route? also thanks for the guide info as I will have Doug check and/or correct the guide clearance since they seem a little tight to me also, any suggestions are welcomed.