Would using roller cam, roller lifters, and roller rockers call for a different or custom pushrod length?

 

Yes, you will need to measure the length when the engine is assembled and order the proper parts.

 

You can order a pushrod length checker from summit or jegs. It is simply an adjustable pushrod. You install it and set the length to get the proper valve to rocker location. Then you remove it measure it and order the proper length pushrods.

Mine are 8.8". The stock 351M/400 pushrods are 9.5".

 

In my case I used all Crane parts and the push rods they sent were fine. You still need to verify the geometry on the engine.