I just install rpm perf head on my sbc with a xe-274 cam since my valve lift is higher than .480" I need long slot rocker.....i can live with that.

only probleme is that I didnt knew that before ordering my parts, thinking I was having stock rocker I ordered +.100" pushrod after install I saw it was wrong

Now with the stock size pushrod it seem find but i dont want to start it until im sure

I would like to know the size of the slot in a stock rocker and in a long slot since my old top end was rebuilt for stock car race


Thanks
Seb

 

Long slot rockers are designed for people who need to run a stamped steel style rocker and have a high lift camshaft. ie: Stock Eliminator cars, some stock car classes. The slot in the rocker allows for higher lift without the end of the slot hitting the rocker stud at max lift. It doesn't hurt to have long slot rockers but if lift is too great with normal rockers, problems will happen with the valve train.

You don't go and order "0.100" longer pushrods without checking the valve train geometry first. Without knowing the exact length you need, overlength pushrods can cause just as much problems as incorrect normal length ones. Many things can determine a length change. Small base circle cams, deck height, head gasket thickness and valve installed length can affect what length pushrod is required. Whenever something is changed that isn't stock, clearances and geometry need to be checked.