I have a '93 LO5 with a factory roller cam. I was recently offered a set of like new, 87+ 1.6 self aligning rockers. Reading here and elsewhere I've yet to find a definitive answer regarding my motor. First, will I need to enlarge the rod holes to accommodate the 1.6's? I was told that cars with self aligning rockers already have larger holes and thus don't need enlarging. Secondly, will I have valve cover clearance issues. This also seems to be hit or miss when people have swapped them.

 

*bump*

Anything?

 

The increased rocker ratio is achieved my moving the pushrod slightly closer to the rocker pedestal. Each head is slightly different so the amount of room for the pushrod hole depends exactly on your head casting. Valve cover clearance comes from the rocker style or brand, not the ratio.

 

I wouldn't mind knowing myself. I'm building a TPI engine with 1.6 rockers and vortec heads.

 

+1


Can't be any more clear than that !


Gonna' have to install the rockers and check the clearence. Once the rockers are installed you can finaly check the stock covers to see if they need fit as-is, need to be "tweeked' to fit, or replaced. Using "short" poly locks helps with fitting many valve covers over Roller Rockers. Baffles can also cause issues......

All just part of the game us gear-heads play !!!!

 

The vortec (96-99) engine I'm using has like 430 or so lift on the stock cam, and I'm using the hot cam kit that has 1.6 rockers and 530 lift. So I just assumed the stock valve covers wouldn't work because the just look so low profile. But that's what mock up is for.

 

So far my stock valve covers have no clearance issues or push rod holes in my vortec heads. But on car craft they say you need to enlarge the holes to 3/8".
But like I said I can see no issues at this time. But I'm also wondering if this will change will a lifter pumped up full of oil.