I use light springs and feeler gauges to check mine but years ago I've used this. It can be bought easily at craft stores.


https://www.google.com/search?q=modeling+clay&ie=utf-8&oe=utf-8

1970 Duster
Edelbrock headed 408
5.984@112.52
422 Indy headed small block
5.982@112.56 mph
9.42@138.27

Livin and lovin life one day at a time