rotary valve

[atoboy04]

can someone tell me, does the 98 670 summit x already use the #501 valve or is the 501 valve an upgrade for the ho motor as well?

 

[Skidoohmx]

It comes standard in those ho motors.

 

[atoboy04]

thanks for info

 

[0neoldfart]

A little info...

It comes standard in those ho motors.

The 670 HO in the 98 Summit X was neither the 501 cut, nor was it timed to the 96 MachZ specs. The one I removed from my stocker was designated as a type 500 RV. The 501 valve works well in the HO motors, but use the timing spec from the 96 Mach Z (with twin pipes). A 99 race manual with a degree wheel will do wonders for that sled. Hope this helps you.