I have done it like that in the past but I used height checking springs and pulled all the spark plugs so that I had a better feel. You can bend a valve pretty easy if it hits.
Of course this does not work with hydraulic lifters.
Unless you bottom the lifters out first.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
