Here's what I came up with to get maximum lift but to still stay in spec
If exhaust is: 305 / 305 / 300 / 300
Use shim___300 /300 / 300 /325*
If intake is: 205 / 220 / 190 / 150**
Use shim____325 /325 /300 /perfect as is
* Be careful with this one. 325 is going to get you very close to 250 clearance. A 300 would be safer, but a 325 should fit if the numbers are right. I'd want to turn the engine over a number of times by hand and measure a 325 shim 8 or 10 times before I fire up.
** This one is dead nuts on perfect as is.
Thanks again to Pat for taking the time to write the shim app.
