Billet Rod - Junior Race Car 4.5"Junior Race Car Billet Rod is for Modified Animal engines but can also be used in the World Formula, LO 206, 1 4 Midget engines. It is 4. 5" from center to center and fits the stroker crank with the . 998" rod journal. It uses a . 490" wrist pin. Must be used on engines with a deck extension attached to the top of the block (DECK) Must also use an aftermarket piston with a . 490" wrist pin. Machining of the top of the piston and the deck is necessary