They used steel shim gaskets for many years with no problems. MLR gaskets are just a different version of steel shim head gaskets. Main deal is surface smoothness of the block and heads. Steel shim and MLR gaskets don't conform much so surface RA should be 30 or better. Most likely the only issue you may have is when you pull the engine apart for service you will have a groove in the heads where the fire ring compresses. And may want to get the head surfaced to install another new gasket, but that is down the road.