Air intake horn bolt size

[97DieselVT]

Looking to see if anyone has the correct bolt size for all 5 bolts that hold the stock air intake horn down (4 on grid heater, 2 long, 2 short and 1 on intake plenum plate) Motor is a 98 12 valve. I believe they are 8mm but cant find the correct length and pitch as i don't have one to compare to and the search function turned up nothing.
any help is greatly appreciated.
Thanks in advance.

 

[hydroshok]

IIRC, 8X1.25. Measure your horn and grid heater, add 1/2" to thread into the head and you should be good.