I have a L98 block in my 86 IROC. Inside the block, I have a LT1 cam. Would I run into trouble if I install a set of 1.7 stainless steal Roller Rockers?

 

Do they make a 1.7 ratio for that particular engine/head?

There's more to going to a higher lift than just the rocker ratio. Everyone knows about piston to valve clearance. Cam timing determines when the valves open and close in relation to where the piston is in the cylinder. Simply going to a higher ratio may cause the valve to hit the piston.

Many people don't realize that there are other clearance issues. Without a full roller rocker, the rocker could bind on the rocker stud if the lift is too great. There's also the clearance between the bottom of the spring retainer and the top of the valve guide/seal. Too much lift and the retainer hits the seal. Lastly is the valve springs. They're only installed to work with a specific amount of lift. Too high a lift and they'll bind and break. Increasing rocker ratio means the pushrod is located closer to the rocker stud. This means the pushrod itself gets moved. Do the pushrod holes through the head or any guideplates allow for this relocation?

Changing rocker ratio is a poor mans cam swap. It's better to install the proper cam and have the heads, valves, springs etc checked to make sure they can handle the increased lift.

 

Good info AlkyIROC. All that process seems too far out of my budget. ill just stick with the 1.6. ratio. Thanks for the help.

 

Yea, big trouble, the max lift on those L98 heads is around .480

 

Right on. Thanks for the info.