I was trying to check piston to valve clearances with clay but the hydraulic roller lifters are not pressurized so I didn't get a good reading. How do I check this without have to buy solid rollers?
My engine is a 454 bored 60 over with stock rods and Speed Pro H693CP .210 domes. The deck only has .005" off to square.
The cam is a Comp Cam XR276 with .510 lift and roller lifters and 3/8" push rods and stock rockers. Installed straight up.
The heads are stock peanut ports 236 with Comp springs, retainers, and keepers to match cam.

Should I be concerned with this 'mild' build about piston to valve clearance?

Also, do you think the stock rockers will work without being 'long slot'?