Before deciding on whether or not spring shimming is necessary....... go to the spring page on the TF site and look up the specs(TFS-16094).
You’ll see they don’t agree with the paperwork that comes with the heads........ but they do agree with the specs that the spring manufacturer shows for that spring(PAC 1294).
On my tester, the springs match the PAC specs.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
