Not sure why they do this but Small block Harlan Sharp rockers are made for longer valves. Custom push rods or lash caps help this situation.



Small Block Mopar V8

Fits
1964-91 "LA" 273-360
Sets

Part # Ratio Price
S70025K 1.5:1 $774.00
S70026K 1.6:1 $853.00

Intake & Exhaust Rockers
70025-1 1.5:1 $ 37.90
70026-1 1.6:1 $ 37.90
Special Notes:
* Needle bearing allow for more oil flow to the rockers.
* Oil restrictors may be necessary to maintain oil pressure.
* Rockers are designed for big lift cams requiring .100 to .150 taller valves.
* Rocker shafts are drilled to allow for 3/8 mounting hardware.
* Rocker spring clearance is limited to 1.500 if more spring clearance is required,
contact our customer service department to discuss your options.



http://www.harlandsharp.com/sb_mopar.htm